I will recommend that you do not take legal actions right now, only because of the cost of consulting a lawyer and other things relating to it. A better option will be to exhaust all the 'free' methods you can use to put pressure on them to act on your case and probably release your funds.

The thing is, centralized services are famous for confiscating people's funds for any reason they can come up with, though i have a feeling that since support is yet to tell you the 'wrong' you have done; and they claim they do not even know what is wrong, then the specific department may probably contact you, but it could take a long time.