Hey so if I want to extend my Xbox Live Gold again with the Microsoft credit (balance) I only get a request that I should add a payment method. Has it anything to do with the fact that Microsoft couldn't withdraw anything from my balance for a month because it was empty? Will my Xbox Live Gold resume if I add a prepaid code and my account will not be blocked after a long period of payment?
I'm only seeing your question now, but I have already answered you by PM.
You are welcome to try this with a prepaid card, but I don't think that will work.
You can't avoid an alternative payment method such as credit card or PayPal. Microsoft wants to make sure that there's no further delay in payment.