Ok, then the best way to use your service is to get a free miner, wait until it generates enough btc to buy a minimal payed miner, buy it, and continue to withdraw profit once in a while without paying you a single satoshi from pocket. I am going to try this right now.
Or you could do some math and not waste your time. To buy 20 GH/s with proceeds from 10 GH/s will take a while. And if double ROI like that would be such an easy thing to do it would make even more sense to buy as many terrabytes as you can afford.
Not at such shitty service, sorry. Good buy.