Their web page prominently points to this discussion thread, and a twitter account. I don't know how else you get in touch with them, but maybe I have not looked hard enough.
Twitter feed seems very hunker dory. The end of this thread less so.

I too, have a lot of coins stuck in exchange. I have 40% mined the minimum (weekly) payout. It would have been 42% but they are stuck in exchange. I am a low hash rate miner and their difficulty settings do not appear to work as advertised. I think I will have to write of the BTC in that account, as I have little motivation to continue mining with them.

Why are they stuck in exchange?
1.) They have mined a coin and a put a sell order on the market which as moved so far against them it is unlikely to be executed in the near term or ever, without manual intervention dumps (which might upset those who believe in the unexchanged balance.)
2.) They have mined a coin which is now so poorly supported that the exchanges wallet does not work and so cannot receive the coins. Limbo transference.
3.) They have mined a coin so rapidly that transactions can't get through because the difficulty is to high for the hash rate support. (can happen with a top 50 kimito gravity well coin)
4.) Other.

I think it is time they started communicating the situation with their customers. We await an enlightened answer.