Refusal of refund and Disrespect

I was very disappointed with the service of the manager blessing.I was charged twice for one meal on the 18/12/15 and was told to come back on the 19/12/15 with just my receipt. When I get there in the morning I was told to get proof from the bank that it was charged twice and no reversal was actually done by the bank. When I retrieved it the manager said my proof is not valid and I must come back after another 24 hours so they can see if im speaking the truth. He was not allowing me to speak and told me to take my papers and go away.i was told that ocean basket is not going to run away with my small amount of money. Being a store manager in another store I would not react or behave the way he did. Please may I have what is mine back and please sort out your management's attitude to customers because it is ridiculous.