In fairness, you should be returning the item to the place of purchase if you can.Such a shame. I think I'll avoid purchasing their products for a while, thanks!
This is taken from OCUK retuns policy
After 30 Days / Warranty Period
Sometimes goods may become faulty after the acceptance period has expired but within the warranty period. Depending on the product, you will receive either a replacement or your product will be repaired.
Reducing the time you are without a working product is important. You can often save time and money by handling the return directly with the manufacturer. We will advise you of this option when appropriate. Please click here to check service availability and contact details by manufacturer.
If a direct service is not available or you would prefer Overclockers UK to handle your return, then we encourage you to contact us. We will send your goods for repair or replacement to the manufacturer under warranty.
Turnaround times vary between manufacturer and product type. Overclockers UK is in constant contact with our suppliers and will endeavour to return the items in the speediest manner possible.
Goods returned for repair or replacement should be sent with all components provided at the time of purchase that are required for the product to work e.g. PSU's require all modular cables, AIO coolers require all mounting hardware, fans and cables. Any additional accessories such as figurines, stickers, keychains etc are not required to be returned as we cannot guarantee that they will remain present with the original item through the return procedure.
If the manufacturer is unable to return the items within 28 days, we will give you the option of a refund. Depending on the age of the items, the refund may include a deduction for the length of time you have used them (known as rescission).