Disgusting service

I purchased a 7" Tablet at Ackermans connect Westgate to communicate with my daughter during school holidays, that was on the 27th Aug, on 20th Sep the tablet went dead, could not turn on could not even charge. I took the tablet back to the shop demanding my money because it didn't even last a month, I was told about a 7 day money back policy and repairs for later than then which have a turn around time of 21 days. Today it's 20th Oct i have been to the shop twice, wrote to customer service and it seems no one knows where the tablet is and how long it's going to take....i have never been so disgusted with a service and I will never spent my money at any ackermans store ever again.