Paypal credit or debit card

Hello guys,

My prepaid card is linked with my paypal and i'm using that paypal account only for making payments thats it, but the problem is that i can't save my paypal account with merchant billing system 'coz its asking for credit or debit card. Without this problem everything is working fine , can anyone please give me some suggestions in this case. (Actually i need to save my paypal account with the merchant billing system)