Can someone here explain something? I purchased after ICO 250$ Dimcoin. @ days ago i saw that i received the coins. now i opened the wallet the coins are gone, no transaction was made, just gone??

How is that possible?
Did you tried with re-login? what's kind your wallet have? If you using depot walley, just waiting to your connection to connected to node, could you see on top left, there colour node is red or green?
I use depotwallet and yes login multiple times and is connected to node. green color.