I don’t have a paypal credit account. But I’m late on my payment?

Description

I have had a paypal account for some time, and it’s linked to a credit card from my bank. Every time I make a paypal purchase, the credit card is billed. So my paypal balance is always paid. I don’t remember creating a « paypal credit » account, and I can’t find any emails from paypal indicating that such an account exists.
But recently I got a notification that my transunion credit rating has dropped because I am late on a payment to paypal credit. I looked at my paypal account, and the balance is $0. I notified Transunion that the paypal credit account that I have a late payment on doesn’t appear to be my account, so maybe it’s identity theft.
Today I got a paper bill from paypal credit, which gives my address, and lists a credit card number, telling me that I’ve been billed a late fee due to an overdue balance. I looked back at paypal.com, and my balance is ZERO. I looked at paypal.com to find some indication of a paypal credit account. I can’t find anything. So I called the number on the bil[Removed. Phone #s not permitted] The AI on the phone tells me they’ve identified my account, and asks me to verify « the last 4 of your social » to access my account. There’s no way to get past this and talk to a real person, and since I don’t think I have an actual account, I don’t want to give them any information at all, especially part of my social security number.
If this is a scam, it’s a particularly sophisticated one. But I don’t know what else it could be. I’m trying to figure out how to get help on this issue, and paypal doesn’t seem to have a number to call from the paypal.com website. My balance in Paypal is zero, so there’s nothing for me to dispute to initiate a conversation. There’s also nothing on the paypal.com that indicates that I have a paypal credit card, so I can’t dispute anything there.
What do I do?