Double payment

Am soooo angry and ****ed, went to rage boitekong to pay my sister's account on the 28th, when i get there the POS machine is not working or rather was giving a problem. I swiped my card twice and the other transaction was declined then the other one was successful, today while at work it shows 300 going off my bank account and i went to the store they told me that customer care says they cant see it, i myself took an initiative to call them by myself where i spoke with lady called ntombi who insisted that they want to talk to the clothing account holder, i mean how is the account holder relevant to this because money went off my bank account not rage account. Mind you i have to take out my daughter's lay-buy with that money. Am so angry am even planning to go to ombudsman i cant tolerate such treatment with my money.