imagePickerControllerDidCancel with UIAlertView not working right

Question

I am trying to present a camera view controller with a custom overlay containing two labels. I have been unable to get my imagePickerControllerDidCancel method and alertView to work properly. The system is printing the correct information to the NSLog but the lines of code that I have written are not doing anything and when the user taps 'Back' (to cancel the alertView and return to the imagePicker) the camera appears again but the takePhoto button and Cancel button are no longer accessible. They can still be seen but not tapped. When the user clicks the button at index 1 (Leave) I want the camera to be dismissed and to take the user back to my homeViewController which is at tabBarController index:1. In addition, when the camera first loads, the timerLabel is displayed with the correct data but then quickly disappears. I feel it has something to do with my refreshLabel method but again, I do not clearly understand where I am going wrong. None of these things are working for me and I'm still very new to the programming world so help with any of these matters would be greatly appreciated. thanks!

    #import "CameraViewController.h"
    #import "FriendsViewController.h"
    #import <mobileCoreServices/UTCoreTypes.h>

    @interface CameraViewController ()

    @end

    @implementation CameraViewController
    @synthesize  titleLabel;
    @synthesize timerLabel;

    - (void)viewDidLoad
    {   [super viewDidLoad];

        self.recipients = [[NSMutableArray alloc] init];
    }


    - (void)viewWillAppear:(BOOL)animated {
            [super viewWillAppear:animated];

        if (self.image == nil &&  [self.videoFilePath length] == 0) {
            self.imagePickerController = [[UIImagePickerController alloc] init];
            self.imagePickerController.delegate = self;
            self.imagePickerController.allowsEditing = NO;
            self.imagePickerController.videoMaximumDuration = 10;

            if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
                self.imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;}

                self.imagePickerController.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:self.imagePickerController.sourceType];
                [self presentViewController:self.imagePickerController animated:NO completion:nil];}

            [[NSBundle mainBundle] loadNibNamed:@"OverlayView" owner:self options:nil];
            self.overlayView.frame = CGRectMake(160,8,0,0);
            self.imagePickerController.cameraOverlayView = self.overlayView;

            NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
            NSString *deadline = [NSString stringWithFormat:@"%@/deadline.txt",
                                  documentsDirectory];
            NSString *name = [NSString stringWithFormat:@"%@/name.txt",
                                   documentsDirectory];
            NSError *fileError;
            titleLabel.text = [NSString stringWithContentsOfFile:name
                                                        encoding:NSASCIIStringEncoding
                                                           error:&fileError];
            timerLabel.text = [NSString stringWithContentsOfFile:deadline
                                                        encoding:NSASCIIStringEncoding
                                                           error:&fileError];
            if(fileError.code == 0){
                NSLog(@"deadline.txt was read successfully with these contents: %@,",
                      timerLabel.text);
                NSLog(@"name.txt was read successfully with these contents: %@,",
                      titleLabel.text);}

            [NSTimer scheduledTimerWithTimeInterval:1
                                             target:self
                                           selector:@selector(refreshLabel)
                                           userInfo:nil
                                            repeats:YES];
    }

    -(void)refreshLabel;{
        self.formatter = [NSDateFormatter new];
        [self.formatter setDateFormat:@"dd:hh:mm:ss"];

        NSDate *startDate = [self.formatter dateFromString:self.timerLabel.text];
        NSDate *timeLeft = [startDate dateByAddingTimeInterval:-1];
        NSTimeInterval totalCountdownInterval = -1;

        NSTimeInterval elapsedTime = [timeLeft timeIntervalSinceNow];
        NSTimeInterval remainingTime = totalCountdownInterval - elapsedTime;

        if (remainingTime <= 0.0) {
            //dismiss controller and set to homecontroller at tabBar index 1
        }
        self.timerLabel.text = [self.formatter stringFromDate:timeLeft];
    }



    - (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {

        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Are you Sure?"
                                                            message:@"you can't come back"
                                                           delegate:self cancelButtonTitle:@"Back" otherButtonTitles:@"Yes", nil];
        [alertView show];
    }

    - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
        if (buttonIndex==1) {
            [self.imagePickerController dismissViewControllerAnimated:NO completion:nil];
            [self.tabBarController setSelectedIndex:1];
            NSLog(@"Leave clicked");
    }
        else {
            [self reset];
            NSLog(@"cancel clicked");
        }
    }
- (void)reset {
    self.image = nil;
    self.videoFilePath = nil;
}