Not sure if anyone can help with this but thought I would ask.
I work a few hours a week in a national retail chain, in my payslip I have noticed a full shifts wages being taken back. I have been told this is because I failed to clock out on one occasion. 
Is this legal - we have been forced to sign special agreements for the new clocking in/out system so is it possible that I have waived any rights I have. I am receiveing pretty much minimum wage.