I have been there as well buying the bonus for £20 and loosing over 10 times in a row. I have been fortunate after keeping going and eventually taking 20 spins, managing to recoup my losses with a bit of profit but buying that bonus on chilli is now on my never again list. I was lucky but i was having the same thought process as yourself. Its my gamblers brain that causes this because my analytical side knows that my thinking is skewed when i think after 10 losses it has to change.
I have played it 5 times so far on 20p stakes and hit the golden chests twice, one went for £170 and the other for £280, i am a bit superstitious if i hit decent wins and tend to leave them for a few weeks after. Sounds like i was really lucky.
KingLicks