You need to contact Customer Services for advice here, and if there are steps for you to follow,  to proceed here, aside from finding a 3 year old invoice !

I strongly recommend contacting CS at 8 a.m. on a weekday as there's more chance of Dublin answering,  only speak to them,  you'll know if it's Ireland calling,  as it's a Call Back option.

Today and Bank Holiday Monday tomorrow,  lines will open at 9 a.m. you can try then too,  but as said,  only speak to Ireland explain there's no possibility of finding a 3 year old invoice,  so what do you need to do now.

CS can be contacted through this link....

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

Good luck,  please do come back and tell how you got on,  hopefully with good news!

@srjgroundworks_3