American Express National Bank agreed to pay a $15 million penalty levied by the Treasury Department’s Office of the Comptroller of the Currency (OCC) for alleged oversight failings regarding a third-party affiliate and its efforts to retain small business customers.

American Express (Amex) failed to ensure it had appropriate call monitoring controls and mechanisms to document and track customer complaints in connection to its unnamed third-party affiliate, the OCC said in a press release Tuesday.

The third-party affiliate was responsible for retaining small business customers. Between 2015 and 2017, Amex had inadequate oversight of the affiliate, the OCC alleged in its consent order, including poor governance, inadequate call monitoring, documentation processes, and handling of customer complaints.