Misleading Customers

Good Day On the 11th of December I had purchased an Acer Aspire Laptop and a Canon Powershot camera from Incredible Connection with it being an online purchase. They were running a promotion whereby if you pay using your visa card the customer will get a 20% discount for purchases not exceeding R10000 which was a good deal. My 2 items which were purchased totalled R11998-00 and after the 20% discount the items totalled R9598-00 which was in line with the 20% promotion. Upon finalising my purchase I noticed that I was not receiving a 20% discount on the checkout screen so before finalising the purchase I decided to contact the call centre directly for assistance. I was 'So Called' assisted by a gentleman by the name of Lookman, not too sure if the spelling is correct. I explained to him that the 20% discount was not pulling through and he advised me to finalise the purchase and thereafter I will receive the discount of 20%. Which I thereafter did and was debited R11998-00. After finalising the purchase and already being debited he thereafter tells me I do not qualify for the 20% cause the initial purchase exceeded R10000. I was extremely iterate as u can imagine and I explained to him that he should have advised me about that before finalising the purchase. He thereafter explained that he will speak to his manager and get back to me in attaining my discount yet he hasn't. I contacted incredible connection later the same day and spoke to a gentleman by the name of Byron and he confirmed to me that the discount of R2400-00 will be credited to my bank account within 3 days( spoke to him at 15:45 on Monday the 11th of December). I didn't get a,confirmation email so thereafter I contact the call centre the next day and spoke to Dillon and he explains to me that I don't qualify for the 20% discount and he will get his manager Isha to contact me after reviewing all calls I had,previously with the agents. ISHA contacts me on the 13th off december and she provided no assistance at all yet only excuses and apologies. She escalated the matter to her customer care centre and she advised me that they will definitely give me a call the same day or the next yet I'm still awaiting a call. This is extremely frustrating to be getting the run around and the buck being passed around with no assistance at all. I'm not willing to pay the amount of R11998-00. The amount I should be paying is R9598-00. please assist with this regard as incredible connection need to accept their error and improper customer service and provide eligible customer service Thank You Pravesh Mothiram ********** 777