Refusing to provide proof of purchase

I bought a phone contract in February 2019 and I registered with an independent insurer so I got ****** a few days ago and I had registered with that insurance using an IMEI number that I had found on my box.so now it sends out my phone had two imeo numbers and my insurance had the first one but telkom is using the second one. when this happened I was in a different town so I went to the nearest telkom store to blacklist my phone quickly before I went to the police station so they gave me the second IMEI number which is the one that I blacklisted and I wrote on my affidavit .so when I got home I had access to the internet and the box of my phone I realise that there are two different IMEI numbers and I had given my insurance and other one and telkom was using a different one so I called them to blacklist the IMEI number that I had registered with my insurance of which they did and gave me a second ITC number. so now I need a proof of purchase with this IMEI number and they are saying they can't do it ,maybe it's because I've only called once today . yesterday I called multiple times and I had a feeling that the person didn't know what they were talking about which of which I was right because the fourth or fifth call centre agent is the one who seamlessly helped me. maybe today I'm just tired and I don't know this doesn't make sense how can they refuse to provide IMEI number that they blacklisted that is on my phone this is very confusing. I'm sorry if it got long and the grammar got bad, I'm using speaker to type this. Telkom can contact me here *** or ***