Programmatically change WooCommerce subscriptions payment method

Question

while adding a new card , if user click particular card to make it "as default" all subscriptions from other cards should be moved to selected card. All of my logic is working fine.

$new_default_card : This variable has new card data (object)
$subscription : This variable has subscription data (object)

I want to update the payment method from other cards to new one.

set_payment_method : This method isn't updating anything rather it remove subscriptions from other cards.

// Get the new default payment method details
$new_default_card = WC_Payment_Tokens::get($token_id);

$payment_method = WC_Payment_Tokens::get_customer_tokens(get_current_user_id());

$user_id = get_current_user_id(); // Get the current user ID

// Query subscriptions using WC_Subscriptions function
$args = array(
    'subscriptions_per_page' => -1, // Get all subscriptions
    'status' => array( 'active', 'on-hold', 'pending', 'cancelled', 'switched', 'expired' ), // 
    'customer_id' => $user_id, // Filter by customer ID
);

$subscription = wcs_get_subscriptions( $args );

$subscription->set_payment_method($payment_method->get_data()['token']);

$subscription->save();

Answer 1

As wcs_get_subscriptions( $args ); is not a WC_Subscription object but an array of WC_Subscription objects, so the method set_payment_method() can't be applied to a non WC_Subscription object and should throw an error…

From your code, try to replace:

$subscription = wcs_get_subscriptions( $args );

$subscription->set_payment_method($payment_method->get_data()['token']);

$subscription->save();

with the following:

// Loop through customer subscriptions
foreach( wcs_get_subscriptions( $args ) as $subscription ) {
    $subscription->set_payment_method($payment_method->get_data()['token']);
    $subscription->save();
}

It should better work…