On June 26, I'd chatted with online support ("sir there is nothing more i can help you with."), and e-mailed the casino manager, Oliver Curran, through their support e-mail address. On June 28, having received no response, I sent him a private message through the Casinomeister forums.
When I'd still no response by July 3 (not even "we're looking into it"), I opened a case with Montana Dispute Resolution, which is the dispute resolution service for the casino software provider, Real Time Gaming.
Today, I received the following:
Dear Travis,I've initiated the withdrawal.
The casino confirmed that they made an error and wish to apologize for that. We have confirmed that $125.00 has already been paid to you and the balance of $275.00 has been credited to your account. Please proceed to either initiate a withdrawal or play with that balance.
The Player Dispute Team
High Rollers Lounge Casino: Reversing the $275 reneg: +$275
Something-out-of-nothing to date: $3,650
I've got concerns now about my Prism Casino withdrawal ($890), but that'll wait until they actually say no.