Black Diamond Casino payment issue

I received an email offer for a bonus at Black Diamond Casino about 5 months ago. I accepted and had some early luck winning about $1200 on one game. This allowed me to play with higher stakes and because of this I quite easily met my playthru after a couple days. I cashed out about $1200 at the end but not before checking to see if I had met my playthru requirements. I talk to a chat representative named Lori. After that I submitted my docs, and of course they requested more docs which I provided. Then after say my docs had been received they have steadfastly refused to pay the withdrawal, and refuse to say on what they based their refusal. They said it would compromise their security if they told me why. I have played online for over 15 years and have good relationships with many sites such as Club World, Miami Club, Online Vegas not to be confused with Vegas Online, Lincoln Slots and many others. I did have a problem with a payout from Slots Madness who now I see is listed as Rogue for being part of the Virtual Group, but they did eventually pay me after about 3 months.

The reason I did not check Black Diamond out more closely is I had played there several years earlier and because of the bonus I decided to give them another try. I had won nearly $1000 previously playing there and they paid quickly without a lot of hassle. I am not sure what they think I did wrong and would dearly love to hear their side of the story. They took my money easy enough! If anyone else has had problems with Black Diamond then maybe they should be listed as rogue. I wonder also if maybe they changed management during the interval that I stopped playing there.