So I'm still having the same problem.
I've been slowly heating it till just gone slightly red then hold it for around another 10/15 seconds...leave it for 19 seconds or so then quench.
It seems that by the time I get to the 3rd size of the round rollers the gold is quite curved/bent and just starting to show signs of cracking, annealing frequently inbetween.
I might contact the local jeweller and and ask if he could kindly show me or even take my gold there to see if there's any problem with it.