Despite what OCUK might try and tell you and irrespective of their policy, they are still responsible under the Consumer Rights Act, not LG.
You can go to the manufacturer if you have a guarantee, but you can also insist that OCUK deal with it, as your statutory consumer rights are against the retailer.
Under the CRA, you can return a faulty item for a refund within 30 days. After 30 days, the retailer has the option of repair, replace or refund.
Also, if you discover a fault in the first 6 months, it's presumed the fault was there when you received the item - i.e. they can't try put the issue on you, unless they can prove it.
TLDR: OCUK are legally obliged to deal with your issue, you don't have to go to LG yourself if you don't want to.
Aye, in the first year, always go through us.