Hmm. I'll gladly yield on this if someone else knows a way, but I don't think there's any way to update your address on Equifax or Transunion directly. You don't have a userid and password with them. You cannot update their data about you directly. If you could, they would be useless. The whole point of credit reporting services is to tell a lender how good or bad a credit risk you are. If you could update the data they have on you, you could change it to say that you're a great credit risk. You're not their customer. The lender is their customer.
Now if your bank or some other lender has your address wrong, you can and should contact the bank and get your address updated. And they'll eventually send the new address to the credit bureaus.
Could the call have been a scam? If they knew your name and phone number and knew that you had applied to this bank for a credit card, I'd say probably not. But did they really know that? Or did they just use some smooth talk and in fact you told them, not the other way around?
I very regularly get emails claiming to be from a big bank or other big company and saying there's some problem with my account and I should click on the link in the email to log in to the web site and verify my account information or some such. Often these are from companies that I have no account with. But they're playing a statistical game. They'll say they're from some big company, like Amazon. Lots of people have accounts with Amazon, so there's a fair chance that a random person will indeed have such an account. It doesn't have to be 90%. They send out millions of these emails, so if even 1% fall for it, that's a lot of victims.
So they could call a random phone number, say, Hi, we're from Bank of America (or whatever, of course), you just applied for a credit card with us and ... If you didn't apply for such a card and hang up, they move on to the next victim on their list. Or maybe they don't even give the bank name, they just say, "You applied for a credit card ..."
Psychics and scammers rely on people volunteering information, they then feed that information back, and the victim forgets that they gave this information and is impressed that the scammer knows it. Like they say, "You applied for a loan with us." And without thinking you say, "Oh, is this Podunk National Bank? Oh, ok ..." Then later they say they're from Podunk National Bank and you think the fact that they know what bank you applied to proves that they're legitimate.
Anyway, I have no idea if it was a scam. It might have been completely legitimate. But if they talked you into giving them financial information about yourself, it could have been a scam.