Shocking

I have a 4 month old hisense 65u8qf television. After 3 months of owning it dark spots appeared on the top center of the set. I reported it to Makro from which I bought it and they logged the service request. The guys came to collect the television set and upon collecting I showed them the problem and they said they can clearly see it and it was taken in. 4 weeks later, 8 phone calls to the call Centre and finally the guys deliver the unit back. Upon them dropping it off the delivery guy tells me that the television is irreparable and I need to get an sms from hisense in order to get a replacement unit. I Phone the call center and they tell me that the technician DID NOT FIND A FAULT.... IT'S CLEAR AS DAY!!! So firstly we take an entire month to find no fault when there clearly is one and now where the hell do I go from here? I spent a lot of money on this television and was really excited about it and getting into more hisense products.... Not anynore