When breaking a bond, some things you MUST do, for your own future's sake. Give the required notice. On or before final day, go into the boss's office with a cheque for the outstanding amount on the bond. Tell him you will exchange it for a clearance letter which clearly states that you are leaving of your own accord and have discharged the bond. Make sure your final paycheque is in the bank, with any accrued leave paid out, before clearing the cheque.
That way, you have ammunition if they later bag you with a poor reference. If you can prove that one, you could sue if any untrue statement had been made. It is also something to take to interview for when any future employer raises doubts about your integrity because of your short period of service after taking the type endorsement training (if they know their stuff they work all this out from your logbook).
But as others have said here and before - if you do a runner you screw those who would follow you. It happened so often in the past and that is why employers now bond. IMHO this is preferable to making the pilot pay up front for the training, but if we as a breed make a practice of snivelling on bonds every operator will require pre-paid training in future.