I can guarantee they have records going back to 1998, when we cruised
DCL for the first time. I had a long phone interaction with DCL Website Support today because DH was shown as Silver on our 2nd DCL cruise last week, but I wasn’t. I had my CC number, and she was able to straighten out my account - apparently the system likes to create new accounts/profiles for CC members and assign new numbers. She even found out DH had more than one profile, too, which explained why we couldn’t get our cruise folio from the website. She merged all our profiles and confirmed our Silver status - my account shows 2 cruises now, as it should.
So I would call them - they’ll straighten things out for you.