You were selling all Brand New items which require a Business Account. You were selling on a Private account which is for selling unwanted used items, such as a garage, wardrobe, attic clear out. This may have caused this restriction.
Only eBay Customer Services can tell you the length of restriction and if changing to a Business Account may help speed up the process of releasing held funds.
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.
@rana_touqeer25