This is bad selling, however unfortunately, no one can make a seller post out an item.
What was the reason they gave on the cancellation? If ' Buyer Requests to Cancel' then you can contact eBay Customer Services explain this is not true, and you were disappointed not to receive the item you won and paid for. This could result in a damaging defect on their account, eBay do not like disappointed buyers!
If you need to, this is the easiest and quickest way to contact eBay Customer Services, for a Call Back option.
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
Lines open 8 a.m. - 10 p.m. on weekdays
9 a.m. - 6 p.m. on weekends.
Automated agents will be available on chat outside of the above hours.
I recommend contacting CS first thing in the morning as there's more chance of Dublin answering.
@rsutton26
