On a very different note than OP, I want to ask you that if you are offering a service that is usable Independently by anyone, how can they keep a watch on people who are using their services to tumble the coins for a criminal cause? If it is brought to their attention then I don't think that Chipmixer guys are the ones who will favor the guy. I have used their services once and I can say that they are punctual at doing their job properly. This thing that OP is facing might be due to them having issues with what happened and so they could be stopping users for some time till their services resume to work normally.
Why should they care? They are not tracking nor analyzing their users. If you want to discuss this, open your own thread.
Also, read the replies before posting stuff (all of the guys above). I already linked a reply from ChipMixer that said the user didn't receive his coins due to a bug and that they gave him his coins. No need to keep speculating like no one knew what happened. Learn to read first, post later.