TV Repair over 6 months

The unit has been booked in 5 times for the same fault No Picture but there is sound, they are refusing to swop it out due to it being out of warranty. The original booking was done 28/05/2017 and the quote (R1850) was paid cash on the 07/06/2017 Here are all the job numbers since the first booking Job Number - 636 Job Number - 662 Job Number - 665 Job Number - 741 Job Number – 836 (current) I would like a full credit of the TV and the repair amount paid in or my money back for the repair in cash as I paid.