Brown Paper Tickets review: Payment not received

Brown Paper Tickets stole our money. They operate as an event advertiser and ticket seller, advertising low fees which makes them attractive to small businesses and non-profits. Our non-profit in Westford, MA raises money for innovative education programs for teachers. We held a fundraiser in May 2022 and used Brown Paper Tickets to process and report on the ticket sales. We had used them once before, in early 2020 before the pandemic. When we went back to them in 2022, their website looked and operated the same as it did before. We had no suspicions that it was just a front. We sold over 300 tickets to an event for nearly $8,000 in sales. They manage the ticket sales and take a small fee. They are supposed to send the balance of the sales within 10 days. It has now been almost four months without payment. There is no phone support, and the only way to communicate with them is through a "support" email address. No one answers it, though. The money we raised represents over 10% of our total budget. We can't afford to lose it! While digging into BPT further, I discovered that our story was not unique. This has been going on for over two years. In fact, the AG of the state of Washington sued them in November 2020 for $6.75 million that they owed to event producers who trusted them. Yet their website continues to operate like nothing is wrong, so unsuspecting small nonprofits and other groups have no idea that they are getting ripped off. What can be done about this?