A homeowner has filed a proposed class action lawsuit accusing Wells Fargo & Co of improperly charging thousands of customers nationwide to lock in interest rates when their mortgage applications were delayed.

Filed on Monday in San Francisco federal court, the lawsuit said Wells Fargo managers pressured employees to blame homeowners for the delays, sometimes by falsely stating that paperwork was missing, so homeowners could be stuck with extra fees.

It comes as Wells Fargo is trying to recover from a scandal that started last year when it came to light that the bank had opened accounts for customers without their authorization in order to boost sales figures.

Last month, a new lawsuit accused it of charging several hundred thousand borrowers for auto insurance they did not request.

Monday’s lawsuit accuses the bank of violating numerous state and federal consumer protection laws, including the U.S. Real Estate Settlement Procedures Act and the U.S. Truth in Lending Act.

A spokesman for Wells Fargo could not immediately be reached for comment.

Earlier this month, Wells Fargo disclosed that the Consumer Financial Protection Bureau was investigating the fees the company charged to lock in interest rates for delayed mortgage loans. In a securities filing, the bank said it was working with regulators to see if customers had been harmed by the fees.

Interest rate locks are guarantees by a lender to lock in a set interest rate, usually for several weeks, while a loan is being processed. If the interest rate lock expires before a loan closes, lenders often cover the cost of extending the lock if the delay was their fault.

Wells Fargo usually locked in rates for 30 to 90 days but often took longer than that to process applications because of understaffing, the lawsuit said. The bank routinely blamed borrowers for the delays and charged them to extend the rate locks, according to the lawsuit.

The fees could be significant, amounting to 0.125 percent to 0.25 percent of the loan amount, the complaint said.

The named plaintiff in the lawsuit, Nevada resident Victor Muniz, said he was charged $287.50 for an interest rate lock extension earlier this year after his application for a mortgage was bogged down by bank delays.

Muniz had been told by a bank employee that Wells Fargo would pay to extend the interest rate lock but a regional manager reversed that decision, the lawsuit said.

The case is Muniz v Wells Fargo & Co, U.S. District Court, California Northern District, No 17-cv-4995.