Had similar experience with Rollbit, they also accused my of holding multiple accounts at Rollbit.com, but after a couple of hours they unlocked my account and fixed the issue.
To this day Im not sure what triggered it, but it was fixed. There were no problems with withdrawals after they enabled my account, fingers crossed they sort it for you as quickly as they did for me.
What did you do to clear it up? It makes 0 sense. I'm being asked by Rollbit to admit to having multiple accounts when this simply isn't true. I have only ever had ONE Rollbit account and I refuse to lie just to resolve this situation. Since I've provided them with the complete truth, I don't understand how to move forward. This is my money that I won legitimately, and I deserve access to it.