If I get you right, you bought the token and paid with dash, it reflected on your wallet initially but now you can't see it no more. I hope you have added the token through "add custom token"? And if yes, where you trying to view the token through etherscan.io? If yes, I will suggest you login to mew and check for the coin there. Cause I had similar issue some time back. I added a token through the custom method and I didn't see it when ever I scan my wallet but when ever I login to mew I see it there. So am guessing that's the problem.