Grey areas in your favour
The biggest grey area phrase is "reasonable amount of time". That is if you bought product XYZ and it is not fit for purpose you can return it in a "reasonable amount of time". This varies depending upon the object. Buying a PC, you can try it and then send it back, say within 14 days, that's reasonable, 6 months is not. If you bought a pair of skis in May during a sale, but never got to use them until November, they then failed to work correctly, you can still take them back, because in the case of the skis, you have not been able to use them during the Summer so first reasonable use would be Winter time.
Since buying things online, I have become a lot more savvy about DSR rules and regs. Any barrow-boy can set up a web shop-front and start turning a profit, as a consumer you have to get savvy else you're going to get turned over.
If you pay by cards, your card issuer has an awful lot of legal muscle which your monthly card ownership fee ( if you pay one ) and interest charges pay for, use it! I have often invoked my credit card company's legal arm to get something sorted. You fight for a week or two with no response, you get card company on it and you tend to get results in hours, not days!
European regs are pretty strong, the 14 day regs, "if for any reason you don't want it, send it back". Lots of retailers don't even know about it, demanding a reason for return is bollocks! Under European DSR I can send any fully working product back inside 14 days and do NOT have to give any reason whatsoever, I may be liable to a postage charge, but nothing else.
Restocking fee? My hairy one! I fought 2 hours on a phone with a well known high-street furniture company about a restocking fee. £1500 item and they wanted 50% restocking fee! I said "Where does it say on the agreement I signed, that I pay a restocking fee if I refuse it?". The chimp on the phone said, "I doesn't have to say it on the agreement, it just applies." LIke f**k does it!!! LISTEN CHIMPY, IT'S A LEGALLY BINDING CONTRACT BETWEEN ME YOU LOT, IT HAS TO STATE OUR OBLIGATIONS TO EACH OTHER IN THE EVENT OF A DISPUTE LIKE THIS!!!! I eventually ended up ranting to their head office before it got waived and I got it sorted and I simply paid £30 send it back.
If all else fails and the sum is relatively small, you have the Small Claims Court at your disposal. You will not be liable for costs at the SCC, the retailer is 100% liable for costs. Last time I looked the SCC can be used for sums like £25-£500 claims, owness on the retailer/supplier.
Check out the various consumer sites, you would not believe how many rights you as a consumer actually have! I am not a trouble maker, I just don't like having someone trying to pull a fast one on me when I know I am in the right.