Refund of debit orders

I submitted a notice of withdrawal this month with a debit order cancellation from the 1st March 2016. I got debited even though the amount in the trust had been refunded to me. Now if I cancel something why am I still being debited. To my surprise this morning I get told that my January funds are also still being held. I mean really now? Cancelled means cancelled, please give me back my money because now I am losing investment income as I type this.