I knew his salary would be very high...you couldn't have afford an exceptional trainer whose salary is pretty cheap after only a few weeks of playing. Like others have suggested (or rather insisted), change your trainer AFTER Friday's training update (if you're giving your future superstar training minutes, that is).
This mistake would have costed you about 100k, but don't get disappointed. Everybody makes silly mistakes at the beginning. I made many mistakes and so did these managers who are giving you advice. Do you have a mentor? I hear that Australia has a mentoring system?