Matress Firm Employee signed me up for credit without consent

What should I do?

Back in September I was at our state fair with my wife, on our way tona concert there.

We had some time to kill so we looked at some mattresses there. Employee comes and talks to us. Told us about the finance deal they were having. Agreed to run only the pre-approval. Didn't sign, initial or even touch his tablet screen. He said I approved for the deal and we could set it up now If I wanted.

Told him we couldn't right then as we'd have to discuss it and have a concert in 5 mins but that he could save it for us and we got his card and number if we wanted it.

That was it. We decided not to. About a week later I get a call about "delivering the matrress I ordered."

Told the lady on the phone we never ordered it. We only did a pre-approval. Checked my emails and I found an order invoice for the matterss and adjustable frame. $3500+. She canceled the order for me.

Then a month ago I recieve a mattress firm credit card in the mail. It wasn't just a financed order for the mattress but a full on credit card. I never initialed, signed, agreed, handshake or anything approving this.

Is that credit fraud? What should I do? Noticed my credit score dipped about 30 points after too.

Edit: He had my full SSN. Hence the pre-approval.