Bad Customer service

I have been their customer since 2017 but now I need a copy of a recording between me and one of their upgrade agents. They affored me an upgrade deal on the 12 February 2021 which I accepted ,when I was still waiting on the delivery after 7days of waiting I called them and they told me they out of stock, but they will tell me when they get stock. On the 10th of March 2021 I get a delivery of the wrong package, when I call to find out why ,I'm being sent from pillar to post. What is fustrating they say I made an upgrade with them on 4 March 2021 and no one called me on that day and I'm sitting with lots of reference numbers , I'm sending none stop emails to the customer care but no one is getting back to me. When speak to their agents they say , we will get a supervisor to call you back ... Up until today no one from cell cell has called me , and I still want all my telephone conversation with then especially the one they I said I took on an upgrade on the 4th March 2021.