problems with cat B 15 Q

This is my 2nd complaint on the same issue. I'm having problems with my phone for more than a month now, I sent it back for repairs for the 3rd fine back to back and everytime I get it back it still don't work .the phone doesn't connect to WiFi and don't move any data to the SD card. Vodacom did reply on my first complaint but its only empty promises and another week passed without a phone for me.just to be clear ,this phone is on contract and I am without the use of it for 6 weeks now. Since they did not give me a lendphone I had to buy a phone just so that I can make and receive calls.my business is taking a beating because I can't receive my email as usual. I honestly don't know what to do anymore and hope that somebody can help me resolving this issue