DSTV problem

My dstv explorer is freezing and rebooting every couple of minutes. I contacted the call centre 2 weeks ago already. They did troubleshooting and could not find the problem. Referring me to a apparently accredited installation centre. 1up installation in Boksburg. They replaced the LNB and all the cables. I paid R1300. Problem not resolved. They arranged more then once to come back, and then don't show up. I have emailed the complaints centre at DSTV and i have made a million phone calls. Logged calls. Have reference numbers and nobody comes back to resolve my problem. The situation is beyond rediculous. I have paid to get my problem fixed and still have the problem. My decoder is just over a year old. This seems to be a very poor product. And i will cancel my subscription if I don't get help in sorting this out soon