I also hate Comet !! they are rip off merchants
A few years ago my nan brought a tv from them. The tv broke, she went back to comet. they wouldnt do anything because she didnt have the recipt.
The only reason she didnt have a receipt is because the man behind the counter told my nan ( 76 at the time) that the printer wasnt working and they would send it in the post
The receipt never turned up !! and as my nan payed cash so bank statement either. the manager came over and said on his systems the tv my nan brought hadnt been sold and the day my nan said she came in !!
It looks like the man who served her had pocketed the money ( over £400) but their was nothing my nan could do.
She did get the tv repaired free but with a receipt she could of had a refund.
I hope you get it sorted