I wonder how you people come to these shady casinos. Before deciding to play there, have you checked the reviews?
https://www.trustpilot.com/review/www.cosmocasino.com. The reviews are very bad. Many people have complained about their ill behavior towards their players. You should be thankful that at least you got your deposit back. Many people are not able to get that much either. Nevertheless, nothing can be done other than battling with their customer support. You set an example for the newbies to never join these types of untrustworthy casinos. Go for casinos with a good reputation like Stake.com and a new yet promising casino like luckydiamond.io.
Yes OP was lucky to have received his deposit back in full because if it happens to be some other casinos, it would have been a straight direct ban or restrictions on OP account without OP being able to access it I think OP should just do away with the casino as he already got his deposit. Maybe look out for another casino but this time a proper research should be done on the casino of choice and looking out for reviews about people opinions or experience with the casino so that he does not have any issues again. I think this would help OP minimise his risk of encountering such situations in the future.