iPhone 5 phone calls

Hi , i got a problem. My iphone 5 after the ios 10 update (as far as i can remember) doesnt make or receive calls, i mean , it goes into phone app, lags a bit ,then a i choose who to call , i tap on the contact , IT LAGS A LOT , It rings the phone im calling , answering and dont hear anything , touchscreen freezed and cant do anything , after 10 secs it shows how much i've talked then freezes again. Dont know what to do . Restored backup. Set up as new , reinserted the sim , dialed *#31#, downgraded , updated ios . None of this works. I dont know what else to do,please help.