Is Prime Option Fx a scam? I would highly appreciate your professional pointof view.

I started my trading with this broker few months ago, but something went wrong when I found my acount was blocked and I could not contact their official customer services. 

Prime Option is thoroughly a scam broker operating without any regulation and should be avoided at all events. The domain of Prime Option is not available now, as most probably it has been suspended, which is always a bad sign. 

In accordance with the information we hold, Prime Optionis an unlicensed broker warned by the Spanish regulator CNMV . You can check the full warning here.

Concerning your situation, if they blocked your account without any reason when there is balance in your account, unfortunately, this must be their way of defrauding your funds. To be honest, the chance of getting your money back is slim, but we still recommend you to report it to your local authorities.