Bad service from Cell C.

I have a contract with Cell C, I have been their customer for more than 8 years, I was Using a Huawei P30 which was Insured with them and Hollard , I upgrade to Huawei 9 Se last year October i ask the consultant who was helping me to also upgrade my Insurance to cover the new device she agreed and assured me that she has done it on the system,I lost my phone on the 26th of February submitted all the documents needed from me , only to find out that the consultant never upgrade my Insurance it is almost a month, i have been sent from post to pillar i dont know what to do anymore ,the consultant is saying that my case is still pending and when u call the Insurance department i get asked if u have proof that i have insured the new device the supervises or team members are never available,they promise to call me back and they never do that,however they are still billing me, I dont know what to do anymore. I will never do any business with Cell C in the future and i will not recommend anyone to do so ,I am busy loosing business because i dont have a reliable phone,can some take responsibility for this matter,replace my Phone or pay me back my premiums, since your staff members are so unprofessional both in stores,call centres and their superiors