Your pool is the best in the world, as I know

Yesterday I was mining from NiceHash at the speed of 20 GH/s but at ProHashing the speed was showing as ~10 GH/s. Unfortunately, I noticed that only after ~5 hours and cancelled the order. I've spent 0.16567330 BTC on this order. This means that about the half of this amount was lost.
Username: neman, Password: a=scrypt n=scrypt
Started: 2017-07-27 16:56:04 UTC+2 Ended: 2017-07-27 22:36:34 UTC+2
The questions are:
- is it a bug or restriction?
- if restriction, where it was published?
- could you please compensate the lost amount?
Thanks and best regards.