Goodmans LD3261HDFVT?

I have a Goodmans LD3261HDFVT television which I bought from Comet and is just over 2 years old, recently a fault developed whereby the top third of the screen is OK but the lower two thirds are red in colour and very blurred and in some scenes totally black, this problem usually occurs when I change channels. Comet charged me £50 for an engineer to visit but the set had cleared and had a normal picture I explained the problem to him but he did not examine the set or offer any explanation to the problem and informed me that they could replace the screen in the house. I received an estimate from Comet for repair at a cost of £306 plus labour but offered me a discount of 35%. I feel that this problem is an inherent fault but cannot get any satisfaction from Comet who claim the fault is due to fair wear & tear. Has anyone experienced this problem and can offer a solution. I contacted Goodmans direct but they informed me that they did not make or sell this set.