Refuse to rectify payment mistake

I made a payment of R400.00 to what I thought it was truworths account using the wrong reference number of identity, then after I saw that I explained to them that I used identity account number as reference instead of truworths cant they allocate it to truworths cause even on the proof of payment account name says truworths just that I made a mistake now the lady says it will be allocated to identity account even though I explained my honest mistake. I paid identity on the same day.

What did they say because I am not working, I have made a mistake cant it be rectified I wasn't aware you using the same account number for identity and truworths even after my honest mistake of trying to pay you say you will put it in identity account while its shows on my proof of payment that the payment was meant for truworths not identity but why cant you just allocate it to truworths cause identity I have already paid. I'm trying to pay but you are refusing assist what kind of store are you. People make mistakes