I had a large win ($5+) at Rushmore and their sister casinos and after 5 months of waiting they chose to refund my deposits and void my winnings.
I signed up through the Casinomeister site and expected to get help should there be any problems, as they were accredited and heavily marketed there.
Unfortunately Max from Casinomeister doesn't want to go into details of my case, it was enough for him that according to the casino I was not a legitimate player. In November I had a smaller win at Slots Oasis, their sister casino, when I had my faxback verified OK and got paid. Those winnings were now retroactively voided, they didn't refund my x-mas deposits in full saying they deducted my November winnings that were paid.
Max from CM told me that he would forward my email to Rushmore but other than that nothing can be done. Rushmore then chose not to answer to that email.
They didn't feel the need that Rushmore should back their claims with some kind of evidence.
I am deeply shocked and looking for help.
By the way, according to their CS, Rushmore fraud department doesn't have a telephone number, and cannot be reached if you dial the support phone number.

Emails sent to them remain unanswered most of the time.