I just received a call, I didnt answer it, but called it back and the message "the mailbox is full" comes on immediately then hangs up.

Suspect telemarketers etc... Ignore the phone number.  I am blocking it from further calls.

Possibly Portfolio Recovery Specialists.

Yes it is. This number is from the Birmingham, AL. office.

This number is obviously becoming busy within the last couple of days.  I just got a call from this number 10 min ago and when answered, the other end hung up.  When I called back within seconds, a recording comes on saying voicemail box is full.

So, I will ignore and report this number......

I got a call from this number at 8:38 PM, no voicemail left. Says it's from Birmingham, AL and I'm from California. So they are at least 10:38pm their time when they called. Who the f(ck calls at 10:38PM?

I called back, says voice box is full and it hangs me up

so I don't know wtf this is.... what telemarketer calls that late? I was pretty sure the law states that calls cant come outside of the 8am-8pm range