Minn. Stat. § 325G.05: DISPUTED ACCOUNTS.

Subdivision 1. Billing information.

Every financial transaction card issuer shall include on each billing statement the name, address, and telephone number of the department designated by it to receive requests by the customer account holder to correct mistakes or make adjustments to the billing statement.

Subd. 2. Required response.

Every financial transaction card issuer, within 30 days of receipt from a customer account holder, in writing at the address specified in subdivision 1, of a questioned or disputed charge, shall conduct an individual inquiry into the facts and send to the customer account holder an explanatory response in clear and definite terms.

Subd. 3. Violation.

A violation of this section shall be treated as a violation of section 325F.69.