Bad customer service

On Sunday the 15th of June 2019 I went to go buy a few items for a family lunch at Checkers in Columbine Avenue and was charged twice for my bowl of 3 cheese salad. I realized this when I got home and decided to call them and spoke to the manager by the name of Ron. I explained to him that I was charged twice for my salad and his response was "then"??.. I was shocked and asked so how will he fix or assist and his response was you can visit the store with your till slip and will refund the one item however you should do so by the 19th in order to qualify for a refund. Wow what a response... no apology whatsoever and he was not even bothered whether do I stay in the area or not and the fact that I took my airtime to even call to report the matter from my cellphone and holding to be transferred to him and to speak to someone that will ask me "then"? I'm really disappointed at the service, now I must drive back with my petrol to go speak to someone that has no customer experience whatsoever or understand what an inconvenience this is to me. I want an apology from him and to be reimbursed my airtime, petrol that I will use to go back to the shop and the extra salad fee that I was charged for.