KFC Double charges

On the 27th of November I visited the kfc at Paradise valley, Durban KZN. I ordered a veg burger and regular chips which came to R 47.80. I was making a payment with my cheque card and entered my pin as instructed by Samke (cashier). After entering my pin, Samke thereafter cancelled the transaction. I asked her why did she do that as I already entered my pin. She told me that she went to check if there are any vegetarian burgers. She made me enter my pin again and this has resulted in the funds leaving my account twice. I complained to kfc head office but all I have is a reference number. This is unacceptable.