Bought a $50 prepaid gift card today. Tried buying a monthly membership. Didn't want to give real info so I bs'ed the address and name during the "checkout" session. Unfortunately, both websites are denying me. How can I purchase the monthly membership on prepaid cards? Is it even possible?

Usually those work the best. You register the card with a zip code only. Then on any site where you check out. just use a fake name, a address of a burger place or something with in that zip code you registered the card in. Don't use the zip code you live in. Alot of prepaid cards won't work with BP and a few other sites but these do.

Yes, its not instant, and takes a while for them to get it, as you have to mail it to Germany.  

There are couple of prepaid cards that work, but most don't.

I haven't tried prepaid CC in a while, but TER is an international payment and almost all prepaids bought and registered in the US do not allow payments to non-US vendors without some sort of approval.  The one that I used that DID work has not worked for several years: no intl payments.  It might even be mandated by Federal Regs not to process essentially cash payments to foreign organizations.  

Maybe they think TER is a T-E-R-orist organization?  

They used TrustCash for a while but someone posted that even TrustCash changed policies or it's not as convenient as it used to be or some reasonable explanation.

If I had to renew today, I'd be using a MO, an envelope and a stamp