Default Verizon G900V with Straight Talk cannot reply calls???

Ok I've been using my GS5 with straight talk for a while now and everything works but replying calls.

And by that I mean if you call me now the phone call under "recent calls" gets to me with +1 800...
If i go and tap there to place a call from recent I get an error from verizon about a supposed "international call"

My phone is also working on H+ but that is just because of the bands I have the not verizon sim card error but that cuz I'm lazy
Other thing is I receive MMS through a group message which is really weird but I think someone talked about that already.

I've tried 2 phones like this already with the same results so if someone knows something plz share

I've tried dealing with assisted dialing but does not make any difference btw.