The Oregon customer said that he received a $28 late fee for missing a line of credit from the store, although he alleges that the transaction went through on time or was “delivered within hours or minutes of that date.”

Home Depot (HD), according to the complaint which was filed in Multnomah County, Oregon, denied the customer’s desire for the fee to be erased from his account.

Per the complaint:

In response to Plaintiff’s explanation of the erroneous late fee, Defendant, Home Depot, embarked upon a harassment campaign designed to bother, vex and leverage Plaintiff. Defendant Home Depot caused dozens of electronic telephone calls to be made to Plaintiff. These calls were difficult to stop.

The unpaid late fee ended up causing a 100-point drop in the customer’s credit, according to the document.

Home Depot responded to Fortune’s request for comment noting that Citi manages its private label credit. A spokesperson for Home Depot said that the company “will tender the suit to them.”

Earlier this year, Fortune reported on the company’s growing footprint with e-commerce.