Sinotec poor quality

Sinotec TV broke down, still under warranty. Took them a week to collect and a month to return. Job No 519282. Very poor picture quality after repair. No more HD quality that I paid for!! What must a person do to get quality service in our country???? I would like the unit to be replaced as they had their 1st and only chance to demonstrate their ability to provide after sale service. Its funny but actually ****es me off.....even the courier guy said he will see me again soon to pick up the TV again as they constantly have to pick up (and pick up again ) Sinotec TV units.

One can only hope for miracles!! Kobus van der Westhuizen ***