When you return an item and it shoes delivery,  the seller has 48 hours to refund you,  if they don't you escalate the case,  eBay step in and force the refund.  Has this time lapsed?  Has the case closed ?  If not escalate now.

If you need to contact Customer Services,   contacting eBay Customer Services is not easy nowadays to get a live agent , but some have had success using the app, otherwise keep typing in ' I wish to speak to an agent' and this too can work.

Use this link to contact CS, if you can try at 8 a.m. on a weekday morning also more chance there for Dublin to answer.

https://www.ebay.co.uk/help/eua?id=5190

Lines open between 8 a.m. to10 p.m. on weekdays.

9 a.m. to 6 p.m. on weekends.

@dinkdonj.ehkv5