Who told you to just take ID ? That is not correct information, you do need that collection code.
Look through your emails, even Spam, eBay messages, and your order details. If it's not there, contact eBay Customer Services. Be aware, you have 7 days to pick up our item from store, once you have been notified it's ready for collection.
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.
@cea1038