Bad service and attitude from Checkers Sixty60

I received 5 Checkers "mini's" on my order of R 1856.00. I should have received 9 as for every R200 one should receive 1 "mini". When I called Checkers Boardwalk Mall, Gqeberha, Abigail said she could not correct this as I was only allocated 5 mini's on the app. I then called the Customer care Line. The agent who answered told me that should I wish to receive the extra 4 minis that I am entitled to, then I should pay R 35 for the delivery thereof. I was at a loss for words! This was not my mistake, why should I have to pay for the mistake Checkers 60 min made? I then requested to speak to her manager. Team Leader, Thado was courteous, but still did not agree that Checkers 60 min had to deliver the 4 "mini's" to me that was short on my delivery. She gave me a ref no and said I should take it to the relevant store and then would receive my mini's. The whole point of ordering on-line is NOT TO GO INTO THE SHOP! Now Checkers expects me to use my own transport to go to the shop to collect the outstanding mini's. This is not the first time that I have had this answer "go into the shop" to solve the problem. I future I will make use of other supermarkets to place my on-line deliveries.