I removed the one where you didn't say anything and just "quoted" other responses.  I'm guessing that was the one you meant emmiee.

blue

I totally agree with you it doesn't make sense.
I checked terms and conditions for one of the casinos where my account was blocked. I choose not to give the name of the casino here, but if anyone is interested I will tell you of course.

"The casino reserves the right to cancel your membership at anytime without notice. Deposits made into your account may be immediately credited back to you."

"The casino has the full discretion to terminate Player's account and any and all winnings in excess of Player's original deposit (INCLUDING THOSE IN ANY ACCOUNT ON ANY CASINO USING THE TOP GAME PLATFORM) may be void."

It is I who use the capital letters of course, because I don't believe my eyes. It would be logical if this statement was followed by "under the following circumstances....." but it's not.
Further down though it is stated that the casino reserves the right to void any winnings and withhold any balance under certain circumstances, fx fraudful behaviour, misleading information, cheating, etc etc. but I found nothing about "bonus abuse", what constitutes it or that it could be a reason for blocking accounts or ending membership.

One should always read T&C thoroughly of course, but I usually don't when I play at fairly reputable casinos.
From now on I will certainly be more careful.
Sending an e-mail to them now asking for the reason, will tell you when i receive an answer.