In message , R
writes

Let's hope TS get things moving for you .. ;-)

They've advised me to write yet another letter and give MFI even more
time to resolve the issue :-( I'm very sceptical about this since I
have received no reply from 3 letters so I don't understand how
another one would help. Oh well I'd better go ahead.

If you do this give them a reasonable time limit (14 days?) and tell
them if not resolved you will make claim in the small claims court.
Seeing as you bought it from a store I would probably take it and see
the manager directly

Did you use a credit card to purchase these (even just for a deposit)

If so at this point I'd make a claim against them
--
Chris French