MasterCare - battle for months, frustrating

Confidence level in MasterCare = Zero My LG sound system has been returned to them 3 times for the same fault, I paid over R3000, and now my system is with them for two months with not even 1 single update, feedback, nothing. I enquired last week and the call center could not reach the Centurion branch, Jock specifically. I logged a query on their website and Cynthia called me, promised to investigate and call me back the same day, it's been 6 days and no return call.

It is a useless battle for months now, complaint after complaint, repeating faults when my system comes back from their workshop, endless follow ups via email and telephone, very frustrating and at this stage I am so drained, and feeling so hopeless when it comes to MasterCare, I am willing to write off my system valued at over R10k! That's how bad it is. What else can I do?