Unfair treatment and customer being mislead

I am a customer and I have an insurance with MTN for my cell phone. I made a claim sometime last month I paid access fee. The problem that I am experiencing it’s their agents including one of their Team leaders that are misleading me I am getting different feedback on every call, TL even promised to listen to the calls and get back to me as she was disputing what I was advised by an agent, that MTN is able to request for authorisation from whoever for top up meaning paying the difference if I am requesting for a phone that has a different balance from what I insured my device with. I have been calling and the agents would put me on hold for more than 5 minutes and due to my busy schedules at work I will end up dropping the call and I even requested a communication via email but no one gets back to me when I call I don’t get to be assisted sufficiently, last week on the 9th an agent told me that device will be out for delivery and I will receive it in 3-5 business day yesterday when I am calling again I am told they have ordered device they don’t have it. I am finding this unfair and poor service from the company.