MTN failing to blacklist my ****** phone

Good day

I have a contract with MTN , which i took years back initially it was a phone minutes and data.

the phone died and i bought myself a phone cash and only kept my data contract with them, i was recently ****** of my phone i did a sim swam fine but MTN as my service provide is failing to assist me with blacklisting my lost phone when i contact customer care they transfer me to contract depart where they tell me they cannot blacklist my phone as they cannot find it on their systems when i get transferred to prepaid team they cannot assist as my line states it's contract.

i need to blacklist the phone and get the ITC number in order for me to claim with my insurance i m being send from pilla to post...... i even went to EastGate and Greenstone branch no assistance they guy that was helping me at Eastgate said he is escalating the issue they will revert back to me this morning no feedback till now.... Can someone please help me yoh ai As soon as this mess is sorted i m cancelling my contract because i cannot believe all this stories so i must have a contract phone to get assistance this is madness