Default [Q] Problems with Samsung Galaxy S3 after flash to PagePlus

Looking for some help / advice..

I own a Sprint Samsung Galaxy S3. I recently had it flashed over to PagePlus and ported my number from At&T. Occasionally my phone says that I am roaming, I've had a couple dropped calls, and I am unable to send picture messages. The company that did the flash uses HoudiniSoft. I exchanged my old iPhone4 for the flash + some cash. I'm starting to think I got fleeced.

I also bought a S2 for my wife, and had it flashed by the same place to Boost Mobile. She has been complaining about her phone also. I'm starting to think that it's the software that they are using.

I'm not very knowledgeable about this stuff. I wish there was more information out there because I would love to learn. Does anyone know how I can correct these issues? Thanks much for any help!