They probably feel aggrieved, but on the face of it you appear to be within your rights. However, if you wrote that you wished to terminate your employment as from 03 Oct, they have taken this at face-value and decided not to demand you give one week's notice. Did you really write this? - because if so, that is why you have been paid to 03 Oct!!
You are entitled to a wage slip, and to be paid for the overtime, plus a correction for any holiday entitlement due.