BAD AFTER SALES SERVICE FROM REPAIR CENTER !!!!

I am making a complaint about the pathetic lack of after-sales service from the repair centre in Jhb. A month ago I took out a contract for Samsung S6, 2 days later I returned the device to the store due to a battery fault. They replaced the device as it was still in the 7-day OBF period. A week after receiving the OBF, it just went blank. Took it back to the store and they also saw the fault and sent it to the repair centre (15 May). To date, there has still been no resolve to this matter and everyone that I've spoken to has not bothered to follow-up or keep me in the loop of any progress. I lost business contacts not having had the opportunity to back-up information before the device died and I am the one making contact with the store and repair centre repeatedly but to no avail - to add to this, I discovered that the device was lost somewhere between the store and repair centre. I am without a device for a month now and there is still no sense of urgency or sense of responsibility to help resolve the matter in an attempt to salvage this long-standing client relationship. I am extremely disappointed that I have to resort to this report in the hope of having the issue resolved.