Hi all I am due to start a new job on January 1st and hAve resigned from my current job, stating very clearly that my last day of employment will be 31st dec 2015. However I have just received my pay slip and P45 which states my last day is 18th dec and my pay reflects a massive decrease because of this. I'm rather annoyed; can I do anything about this? I've checked my contract and it states I have to give one terms notice, which I have followed. I resigned by the deadline in October. I don't really understand why they have done this. What shall I do?