Sinotech Tablet serviced and returned not working

Sinotech Tablet was sent for repairs 5.10.15, Paid R550.00 for the repairs,collected on the 21.12.15, tablet is not working. Taken back on 22/12/15, was told it will be sent back to Sinotech and will receive it back before the 1.1.2016. I have called Sinotech and they are closing now and opening on the 4.1.16. How is it possible to take a customers money, and tell them you going to send it in again, and tell them its going to be repaired when you know the company is closing. Pathetic service, my son has been waiting in the store for more than 1 hour and nothing has been done. I called the Store Manager - REginald who said he is going to the customer service counter, and will call back, this also takes more time than anything else. There is no CUSTOMER SERVICE - AND NO SENSE OF URGENCY!!!!!! I called the H/O and spoke with James Herman - who also said he will call back, and nothing happened after 1 hour, i called Rabia from HOand i am still waiting AGAIN!!!DO I NEED TO TAKE IT FURTHER THAN THIS AND GO TO DIRECTORS?