5th Time no results

This has been ongoing for months now and I am at wits end. I have a Samsung Galaxy S4 on contract with Vodacom. My phone keeps throwing out a message that there is no simcard inserted .... restart. The first time we did a sim swop and the same message appeared. All the other times, I have booked my phone in, waited for days and then when I fetch the \fixed"phone and I switch it on"