Pathetic Service

I took my Samsung J5 which does not want to send any Whatsapp msgs to Randfontein Cell c about 3x the consultant then checked the phone connected via wifi and it worked i left the store got home it worked for a day and stopped went back the same thing and went back again. my 3rd visit to the store the cell got booked in for repairs *** on the 21/11/2015. i was advised that it would take 21 business days. on the 25/11/2015 :Dear valued Cell C Customer. Your device as been dispatched from the Cell C Advanced Repair Centre. Your reference number is CLC***. 17/12/2015 past the due date i got to the store and guess what the phone is still not back the consultant takes my details down and says she will contact the repair centre tomorrow( today )and enquire what the delay is and give me a call. it is now 12:30 still no call. as per the repair centre no fault was found. I FEEL THAT THERE IS A FAULT AND DO NOT WANT THAT PHONE ANY MORE. AT THE END OF THE DAY I'M GOING TO PAY FOR SOMETHING THAT I CANNOT EVEN ENJOY. I AM APPALLED BY THE SERVICE I HAVE RECEIVED AND NOW IT SEEM LIKE I'M IMAGINING THAT THERE IS SOMETHING WRONG WITH THE SAID SUMSANG J5. Levi