Once automatic feedback is left a buyer can change it if they wish.
This is bad selling on your seller's behalf, nothing can be done to force a seller to send a paid for item, but selecting the reason ' Buyer Requests to Cancel' means they do not receive any defects on their account.
You can if you wish, contact Customer Services, explain you did not authorise the cancellation and were disappointed not to receive your item. eBay do not like unhappy buyers, and may well place that damaging defect on the seller's account.
If you wish to, this is the easiest and quickest way to contact eBay Customer Services, for a Call Back option.
eBay Customer Service
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.
@shirley6578