Had enough!!!!!

I received a call from ismart in November 2019 advising that a diet order in January 2019 did not go through. After having checked I discovered that this was correct but an eft payment was made in January 2019 and I sent through proof of payment. I have since received over 16 calls regarding the same issue and was even advised that this is a system error and will be resolved. I've sent emails with proof of payment and still no joy. Today I received a call from a very rude Miss Jordaan who insisted after I explained this problem to her, that I am wrong and that in fact it was the February debit order. This is not the case as I have checked my account and all the debit orders have gone through successfully. I asked her if i could speak to her manager, which she refused. This is extremely frustrating and today I have lost my cool as I feel i have every right to given this situation. I need this problem resolved. It's frustrating and even more so when you get a rude call centre agent like Miss Jordaan who will not understand that I have been explaining this over and over again. Please get this resolved urgently!!!