Betsafe Casino - Betsafe removed winnings without proper explanation

Betsafe have left me absolutely fuming, I won £3,838 and they are refusing to pay out!! My stomach dropped when I read the email saying they had removed my winnings and closed my account (with no explanation). I went straight on live chat and they told me that they have come to the decision ‘after reviewing your game activity’. How my gaming activity has been a breach of the terms and conditions I don’t know and no one at Betsafe will explain this to me. I didn’t exceed the maximum bet stated in their terms and I didn’t play any excluded games. They have sent me a vague overview of the term’s that they’re accusing me of breaking:
Bonus offers are only available once per person, family, household, address, e-mail address, credit card number and / or IP address.
This decision has been taken in accordance with the following Terms and Conditions of our website:
12.7 We have the right to refuse any player the right to Bonus or to alter the Bonus (including cancellation), if we believe that:
the Bonus is being abused (our definition of abuse includes a player making use of promotional offers without ever risking their own funds);
technical issues have occurred in relation to the Bonus;
the Bonus is, for any reason, not able to be conducted as planned.
12.8 If there is any evidence of abuse or fraud, we will close Your Account and withhold any existing funds.

I asked them to be more specific because I haven’t broken any of these terms. I only have one Betsafe account and no one in my household or family has claimed the bonus.
Their definition of abuse ‘includes a player making use of promotional offers without ever risking their own funds’. With the amount of wagering and the size of my deposit how could this not be a risk of my funds?
I have read through the terms again and again and I’m certain I haven’t broken them. I’ve emailed Betsafe customer service asking them to be more specific about what term they are accusing me of breaking but they only refer me to the same paragraph from their terms.
Betsafe won’t confirm what term I have supposedly broken and won’t tell me how they came to that conclusion except for my ‘gaming activity’. I am all out of ideas and getting nowhere talking to Betsafe, any help or advice would be gratefully received.