No Mobile Network Found

[BadBlood7984]

Does anyone know what I need to do to fix this? For the past month my service will stop receiving texts and calls. My data still works, full bars, but people will tell me they called and it goes to voice mail, people say they've texted and I get nothing. When I send a text, it says pending and displays a "no mobile network found" error. The only way I can get this fixed is to make a call to someone, then all the delayed texts coming rushing in, 20-30 within seconds. I've Googled and was advised to factory restore, that did not fix it, I was told to remove my SIM and put it back in, that did not fix it. Does anyone know what I should do?? I was also told my SIM is bad and I needed a new one? I'm using Straight Talk so I can switch SIMs from VZW to AT&T but I hate AT&T, so I would like to keep using the same towers or whatever my current SIM uses (I'm not tech savvy). Walmart knows nothing when I asked for help, Straight Talk customer service you just can not understand, and they also know less than Walmart.