I have purchase an enterprise license for Xamarin iOS in dec-2015. Which I am currently running on my Xamarin Studios in Mac OS X.
I would like to purchase another license for Android , But in Xamarin portal pricing option for enterprise is not available now.
Please let me know whether everything is free in Xamarin now, if you want to develop and distribute both ioS and Android from Xamarin Studios.
And what will happen if amount is already paid and services is processing under license of one platform.
Everything is free, now and open source as well :). There are enterprise licences which include support and some enterprise features (like bytecode hiding). But the pricing of this is not public. You have to contact Xamarin. If you don't need the editional features, you can just use the free version. It works with Xamarin Studio and Visual Studio. You can try to get a refund, but this is up to your negotiating skills and the customer support.
https://www.xamarin.com/compare-visual-studio