Debited for Service that was not delivered. No refund given to me

On the 3rd October I asked home connect to upgrade my wifi speed from 20meg line to 40 meg line. They gladly did so by taking my bank account details and debiting my account for R500 (Please note they made the debit on their side). They did not upgrade my line to 40megs. When I asked for a refund they said sorry we cannot give you a refund because we cannot find where we have placed your payment. They took the money out of my bank account and then said they do not know where it is so we cannot return your money. I have contacted my bank to confirm they have debited my account and my bank gladly showed them proof. But they refused to return the money they took for a service they did not provide. I have spent the last 2 months trying to get my money back and everyone that I contact simply says they can see that homeconnect has debited my bank account but they do not know where they placed the payment so my money is unfortunately gone.

From a customer stand point, does it make sense for a service provider to debit your bank account, not provide you with a service that they took money out off your account for and then say sorry we took your money, did not give you the service we charged you for and cannot refund you. They pretty much got free money from me and I am extremely disappointed and concerned about the ethnical nature of this company.