Double Debit

My debit order always comes off on the 25th of each month. However, on the 25th of April it didn't go off. I then called MTN on numerous occasions trying to get this sorted out and no one could help me. Then finally got through to an agent who was able to help me. She said a debit order of R627 would go off on the 2nd of May oc which it never did. To my surprise on the 5th May a double debit went off. I have been trying to get my money back for the past 2 weeks an each agent feeds me a different story. I have a thousand references from trying to sort this out. This is bot kn especially because of what we are going through with our economy.