We cannot do that, but you can,  this way:

If you are still within 30 days of the item's last estimated date for delivery,  proceed this way:

Go right of the item in your Purchase History and from More Actions select Return this item. Select the reason Item Not as Described >> Does Not Match Description or Photos. The seller needs to either refund you in 3 days, or issue a pre paid return label for the return of their item. Once the item is received, they have 48 hours to refund you.

If this doesn't happen, you need to escalate to eBay, eBay step in and force the refund.

Listen to no excuses or promises from the seller to close the case early, and do not forget to escalate.

If you wish to buy on eBay it's worth reading their 30 day MBG Money Back Guarantee policy.  It is written on every listing except Classified ads,  and can save you a lot of time and money in the long run.

I've included a link below to explain the MBG,  too.

https://pages.ebay.co.uk/ebay-money-back-guarantee/

@rob-267051 

When you use the correct procedure do not close case on any promises, you must get a refund first and buy again.  That is the only safe way as once closed you cannot open another case.