Invoice request

I have purchased airtime 4 times on the MTN app using the company credit card and did not receive the invoices, I need these invoices for recon purposes. I have sent numerous emails tocustomer care but still no response they always say within 24 to 48 hours andit has been over 4 months and I am still waiting. I tried calling the call centre but I will hold for over an hour and being taken from one consultant to the other. I even went to the branch in Rosebank and the said they cant help. Who is the relevant person to assist me, how difficult is it to retrive purchase history?