U.S. Bancorp Credit Card Complaint

U.S. Bancorp Credit card department,

Billing disputes Indiana

I advised my credit card company of unauthorized transactions that took place in -. I live in -, and have not traveled to -. My credit card company temporarily credited me for the items, until this past week. They sent me a letter stating that as I had not reported my cards lost or stolen, and that since the card was used with a chip reader - I am fully liable for the transaction. I did not report any cards lost or stolen as I have them in my possession ( - cards -the joint account holder and myself ). They then reposted the transaction and billed my account. They did not do anything else to investigate, I am truly concerned and upset as how they were able to use my chip.