tMobile Galaxy II S issue, Phone auctomatically calls blacklisted numbers

I have a Galaxy II S from TMobile. I have several numbers on the Blacklist. When a call from a blacklisted number comes in, my phone rejects it but automatically calls it back. Sometimes there will be a re-call sitting on my phone for 2 hours because a blacklisted number called (no audible notifications when a blacklisted number calls) so I do not know that someone called.

It's a flaw, I know, but is there anyway to fix it. If someone that is not on the blacklisted number is trying to call me, I will never know because the phone won't "ring" when it's already on a call.

Otherwise, I love this phone!

Thanks!