Dont use this insurance!

This has to be the worst insurance company ever! I have been trying to cancel my insurance with them since January. The insurance is apparently cancelled but mtn is still billing me. They have now told me to call mtn so that I can get my invoices from mtn so that the cancellation can be escalated and finalised. I have sent them invoices for Jan - Mar but no they cant use these because I actually need April. Can the insurance not communicate with mtn for documentation? Why is the consumer running around like this? These type of business processes are a waste of time and very frustrating to the end consumers. In the meantime mtn is saying I owe then and are affecting my credit score.