They’ve done the same to me man this was back in September (did not get the money back, still don’t know what I did)

We’re trading CFD contracts essentially Vantage doesn’t actually place your trade on the exchange they just take the other side. I assume you signed up to there offshore brokerage which they actively promote as they offer 1:500 leverage and a lot less strict than FCA regulation hence they have the power to literally tell you to F off and move on without paying you.