On Fri, 10 May 2013 13:29:05 +0000 (UTC), R D S wrote:

Fulfilled all the conditions including scanning the invoice and
uploading it on their website. No cashback forthcoming.

Several emails later with them claiming I never provided an invoice I
scanned and emailled the invoice on a promise it would be sorted.

Never trust email, doubly so for corporates when you are trying to get
money out of them. I used snail mail...

--
Cheers
Dave.