Not receiving texts??

I can make and receive calls, and I can send texts, but I can't receive them. The few I've received are 20 minutes old and I'm not getting any when they are sent. 

I have tried contacting support but you can guess how that went. 

Yes I've turned my phone off and on, cleared cache, used default messaging app, obviously my sim card and network are fine. 

This is really frustrating. Especially considering I barely get service half the time, so what am I paying for??