Cryptocurrency Theft

So I have been using CoinPot for the past 2 years. For some reason, they will not accept my key anymore. They also won't reply to my emails with my info they needed in them. So now, I am afraid I lost all my bitcoin,dogecoin,dashcoin,litecoin among others. This is a sad world. I worked hard on collecting all this. They have not replied to any emails in the past 2 months. Goes to show you can't trust anyone or anything.