Wrong airtime purchase

I accidentally purchased online a R16 airtime meant for MTN. The number I inserted is correct but instead of choosing MTN, I chose Cell C. The money was subsequently debited from my account but I wasn't credited with airtime. I phoned my bank (Standard bank) and they said I need to speak to Cell C for a refund. Cell C responded to my complaint and said the bank should actually help as they are the one who debited my account. I phoned the bank and i was told i will have to use R26 to trace the R16 airtime. Please, who does this to a loyal customer? If this was a larger amount of airtime, would they not help? if they don't resolve this matter, I will close my account with them. CUSTOMERS DESERVE HELP, AND THE BEST POSSIBLE.