As others have said - check your contract, but, also ask them for a copy of your contract... (and from reading other comments, maybe keep this for the 2nd meeting to delay until a 3rd?)
I was quite surprised when I changed roles a few years ago that the (large, global) company had only a single piece of paper with my NI details on. Nothing else.
If their copy is different, of course check the dates - I'm not a lawyer - but you might be able to pick the "better" version...
If you have things like overtime, then maybe you'll be able to take advantage of that to claim more income whilst you close out actions... or... dunno... get an eye test and claim it back...?