I'm curious about this part, do you mean that Vietnam doesn't allow online casinos to operate in their jurisdiction? do online casinos need a license given by the government of Vietnam in order to be able to operate in their country?

anyway, I don't know what exactly is said in the screenshot you shared (I can't understand the screenshot you shared since it is in Vietnamese) but based on your post, they accuse you of cheating on their live games. right now it looks like they are rechecking your case, hopefully, it can be resolved here but if they aren't able to resolve your case here, you can post your complaint to casino.guru or askgamblers, they can act as a mediator and review your case and hopefully resolve the case also.