If I may put my 2 pence worth in here. The SOGA which I believe was amended states that the burden of proof lies with the consumer to prove the product was inherently faulty and not fit for purpose from 6 months after date of purchase, and while I agree your contract is with Comet not Samsung you have had 17 months use out of the product and as such it is reasonable for Comet to expect you to contribute something towards the repair,typically this would be 30% of the cost up to 18 months.Of course it is for the court to decide.

What most people fail to realise that in law when you buy something from a retailer unless it is faulty,mis described,mis-sold or not fit for purpose you aren't entitled to a refund anyway. If the product did not produce a fault instore then is it right that you should be entitled to a refund of a product that is none of the above.

I work for a retailer that sells this model,the overheating is sometimes a result of updates changing power management settings causing the unit to pull more power and the overheating issue.It doesn't just effect your model,one of which I have myself.There was a bios upgrade on Acer software/support section to resolve this issue. Question is most Comet stores don't have internet access and may have directed you to Acer tech support who would have talked you through the process meaning you wouldn't have been without your laptop while it was sent away.