Hello All!!

Ok, i need help on this. My mom has a cell phone, its CDMA,LTE. But i wanted to get her on the same service i use. its a tracfone sm-s120vl samsung luma that was using Total wireless. But ok, i use redpocket mobile. they are like tracfone and use every carrier. i talked to there tech people they said her phone would work fine on AT&T and Sprints GSM system through them, (CDMA service has to have HD calling to work and it does not) but the phone would only use LTE G3 and wouldent be a big deal at all. Ok i got the sim, it gives me 4 bars of service and can text but not make calls. What would do that?? the phone is Unlocked ( i got the code from TotalWireless and it worked first try) the phone says everything is connected but says the phone dont have a phone number. I rest the Networks and they even sent me a new sim in case it was defective, but both sims did the same thing. What the heck can i do? the phone texts and i didnt have to mess with the APN at all, but i did set up the APN and got the same result. When you try to call it says NO SIM OR SIM ERROR. what can i do?? i talked to there techs over and over again and over and over again i hear..take out the sim and restart ..blah blah blah... yeah i didnt think of that the first 500 times... but they say the phone look great on there system and should be working. anyone got any ideas here????