The online bank Simple shut down on Saturday and was supposed to seamlessly transition customers’ accounts over to its parent company, BBVA. But instead, many users found themselves unable to access their bank account at all, as BBVA’s website returned an assortment of error messages, from “system error” to warnings that their account information was mismatched.

The transition has gone so poorly that BBVA’s US website now opens on a large red banner warning users of extended customer service wait times. Anyone who visits the Simple transition page will see a different red banner, apologizing for the issues.

“To Simple customers converting to BBVA: This has not been a good conversion experience for many of you,” part of the message reads. “We know this, and we sincerely apologize.”

Simple opened to customers in 2012 and was supposed to offer a digital-first approach to banking. In fewer words, it was supposed to be “a bank that doesn’t suck,” to quote one of its co-founders. The service had a website and app that broke down your spending and made it easy to categorize payments, send money, and set savings goals. It was purchased by BBVA in 2014.

BBVA said in January that it would be shutting down Simple later in 2021. The decision came from the company “reassessing its goals” as part of a planned sale to PNC Bank, which reached an agreement to acquire BBVA’s US operations in November 2020. The acquisition has not yet closed.

Accounts were successfully transitioned from Simple to BBVA on Saturday, but technical issues prevented customers from logging in, a BBVA spokesperson told The Verge. That led to a cascading series of problems. “Due to the volume of customers attempting to enroll in mobile and online banking simultaneously, there were technical difficulties with the enrollment process, leading to high call volume in our call centers, which overwhelmed the system, and created longer than normal wait times,” the spokesperson said.

Debit cards, ATMs, checks, and scheduled transactions still functioned properly, according to the spokesperson. Though online and mobile account access remains unavailable for users encountering issues.

“We know this conversion process was not smooth for our incoming Simple customers and we sincerely apologize to them,” the spokesperson said. “We are working to make it right, including extending hours in our call center and adding staff to handle the incoming calls.”

It seems that some people have been able to gain access to their accounts after waiting or working with BBVA’s customer service. Judging by reactions on Twitter from Simple’s very online user base, plenty of people still don’t have access though and have been unable to get help from BBVA’s customer service.

BBVA hasn’t provided a timeline for when it expects to restore account access for all Simple users. In its banner message, BBVA wrote that the company is “working to get it back online as soon as possible.”