Deduction after policy is cancelled

Dignity group deducted on my payroll while the policy is cancelled and they are telling me they can not give me my money because of the persal sytem , why keep a premium of a cancelled policy? even if you deducted it the cancellation date is the for a reason if I had to claim after that you would not consider my claim but you expect me to be OK with you taking my money? Im glad i cancelled this ****