Contact the seller if they are not helpful open a case for item not as described in the Resolution Centre.
https://resolutioncentre.ebay.co.uk
Escalate on day 4 if not refunded beforehand, and eBay step in and force the refund.
If the seller wants the wrong item back first, they pay for this postage.
Do not close the case early on any excuse or promise the seller may give, and do not forget to escalate.
