And the funny thing is that the site supports 19 different languages, respectively, the section "Terms and Conditions" is translated into all available 19 languages. And Clause 2.1. in "Terms and Conditions", where it says about the ban on players from Russia is only on the English version of the site. No other language has this item.
You are right on this point. The clause 2.1 isn't available in the other version of the terms, except English. There are 11 clauses under the "(2) General Terms" in English version, where there are 10 clauses in other language version. Perhaps, they have added the clause 2.1 recently.
BTW, do you still have access to your account? You should share some evidence here to make your claim valid. Screenshot of the deposit and withdrawal history, screenshot of the conversations with their support agent.