I would give them a call back and ask for it to be reversed. Roaming in Ireland has no charges within your allowances. ee.co.uk/roaming - pop in Ireland, choose plan after July 2021 and then no max plan or pass and it confirms no charges within allowance.Oh, really?
I was under the idea there was a delay charge, and since I have 4 lines I called up to check if I could get a better deal, and was sold a £10 addon for each line.