J.P. Morgan Chase & Co, a leading global financial services provider and one of the largest banking institutions in the US, was sued for charging undeclared fees to customers who used their credit cards to purchase cryptocurrency, treating the purchases as cash advances, Reuters reported April 11.

The lawsuit was filed on Tuesday in a federal court in Manhattan on behalf of a proposed nationwide class, accusing the bank for charging additional fees, sky-high interest rates on the “cash advances”, and refusing to refund the charges to customers who complained.

Brady Tucker, the plaintiff, claims the bank charged him $143.30 in fees and $20.61 in interest charges for cryptocurrency transactions he made in January and February. Tucker made an attempt to dispute the charges through Chase’s customer service line, but the bank refused.

The lawsuit claims that J.P. Morgan Chase & Co violated the US Truth in Lending Act, which requires the disclosure of policy changes to customers in written form. The lawsuit asks to “recover [Tucker’s] and the Class’s actual financial damages, plus statutory damages in the aggregate amount of $1 million, plus his costs of this action and reasonable attorneys’ fees and expenses incurred therein”, according to the complaint submitted to the court.

On Feb. 3, Chase joined a wave of banks banning customers from cryptocurrency purchases with credit cards The bank later stated that financial institutions can “face the risk that payment processing and other services could be disrupted by technologies, such as cryptocurrencies.”

A representative of J.P. Morgan Chase & Co declined to comment on the legal claim, stating that customers can continue using their Chase debit cards to buy cryptocurrency.