This is very frustrating. I sympathize with you. Unfortunately, these sort of shenanigans are all too common with fintech companies.
I had a similar experience with River, except my account was cance...
Correction: River liquidated my BTC immediately when they closed the account, but delayed the fiat transfer for four weeks. Not only did this result in losses, but bitcoin had rebounded by the time I got the fiat, so I bought back in at a higher price. Arg!