UPDATE: okay, I contacted Scan's Returns team yesterday, and I got into touch with someone called Gareth.
He managed to send an email to the manager about whether I can get a refund on my PSU, but this morning I got a reply from him saying that because of the length of time I had my PSU (still got a month's warranty left as I speak) I can't get a refund.
We went into a discussion about how the warranty on the PowerCool PSU, and as it was 12 months I thought I could still get something out of it back. Apparently, the only option was to replace it like for like, which kinda defeats the object of fixing a PC that went wrong because of that brand of PSU.
IMO that kinda sucks because for one thing, I'm saving up for another giant build, so I won't be able to procure extra funds just to fix my existing build.
To be honest, I can only spend about £15 more on a new PSU, so it would have been nice if Scan would offer me some sort of refund , of which the money could be added with the £15 to buy a better PSU.
Please help!