Now back to my challenge: I've deposited
this transaction, used the default Service fee (I'm not telling you how much exactly), set a delay anywhere from 0 to 23 hours (I'm not telling you my choice), and I lowered the fee
because fees are low.
Did you sent them to a P2SH adress? I've found a trail but it seems that this one would a bit too obvious to actually be your receiving adress (+ the fact that the fees are actually a tad bit high on the transaction itself...).
https://blockchain.info/address/36mQBHnqaoN9h1vcDfuEhx3xa1hxS1k1ZGThat's my address

The first person to post my receiving address (OP excluded
), receives the funds. This offer expires in a week.
Note: at the time I post this, my deposit is still unconfirmed and the return transaction hasn't been sent yet. It does say "BTC received. Awaiting 1 confirmation".
My best guess is the address
1BSNnBo9dQvjWgu1NqhfYWdmRM2fv73oxy, with
this being your mixing transaction. Only reasonable possibility I see.