I kinda had a similar problem with an older BB 8703e a while ago, it was from verizon but it wouldn't take ##000000 because the spc got corrupted somehow.
I couldn't fix it with CDMA WS, QPST or QXDM.

The only program that fixed it was uniCDMA, I just had to rewrite it and it worked perfectly afterwards. You don't have memory access on the 9550 so it might not work but just give it a shot and see how it goes.