So you knew it was refurbished?
You knew it was only supported by a 30-day warranty?
I'm guessing you bought it despite knowing this, because it was cheaper than a new one?
My understanding is therefore that the item was fit for the purpose, as described by both the manufacturer and the retailers, ie guaranteed for 30 days. It is now outside those 30 days and whilst it has gone ****-up, it has lasted those 30 days.
The manufacturer said it would last at least 30 days. It has done so and is/was therefore fit for the purpose they described.
Your contract of sale, however, is with the retailer. Unless the retailer has described a purpose different to that of the manufacturer, the above applies equally. There is nothing else immediately springing to mind about the terms or conditions of sale that I think the retailer has breached.
TLR - Tough luck. You got what you paid for.
Get a new one. They're not that expensive and, to be honest, I can't see Trading Standards taking either Scan or Corsair to court and forcing them to refund/replace your item over a matter of less than £20!!