Usually a gambling sites ask for KYC if they think the user has misused their service by creating multi account. In this case their claim of multi-account and/or asking for KYC purposed the same.

According to the terms of stake.com they can ask KYC as well as location at anytime from their users. So, you should provide them. But according to you, you cant do that as you are using from a restricted country. It can happen if you use multi-account too. So, it is difficult to understand you are lying or not. Anyway, as it is mentioned on their terms and conditions you should not have violated their terms.