bad service

I bought shoes at total sport, I had to take back a pair because the size was small. While busy with the exchange I was told my credit was revoked the assistant then phoned customer services when this natasha person failed to hold back on her rudeness when I told her I didn't understand why my credit was taken back. She told me I overspent on my credit but couldn't tell me when or where cos really I don't understand. I'm very disappointed and am not happy at all with the way she treated me.