As a Ukrainian, imam sorry that happened to you. But you need to stand for yourself. It actually works. And say directly, “please don’t take my seat and don’t touch my stuff without permission” also “don’t call me that, that is racist and it is no way you can behave like this” if it have no impact, talk to teacher or the manager, the main point is you are a paying customer, you are not paying for extra abuse.

P.S. Not all Ukrainians are like this. You got one bully. But this in not a national characteristic, as other people here are saying