Joo Casino - Refusing to pay winnings citing violation of some undefined term

I've been playing at Joo casino for a long time and was actually with a VIP status. I've never had any problems there before this. 2 weeks ago I took their Tuesday 55% deposit bonus with a deposit of 182€, wagered through it and finished with a balance of 1737€.

Next day I received an email that I have been abusing their promotions, which I haven't. I've read the T&C through several times after and prior to this incident and there is nothing stating such.

Now they are refusing to pay my winnings + informed me that since I have broken their terms they will not return my deposit.

I asked them to outline which terms I've broken but they were unwilling to say, simply stating that I have broken their T&C.

As far as I know I haven't broken any terms.