Incorrect Billing

This is now the second review I am doing regarding Discovery. Seems like poor service is not just with one division, but with all. I was approved for Chronic medication after jumping through multiple hoops, as I was a failure on the cheap medication Discovery are willing to cover. The approval stated it would be covered for a year, at a The****utic value (don't know what this means as I cannot take any other medication, but a little T&C should they need to fall behind same). My medication has been covered in full for 5 months, and on the last month of the old script, they decide to cover less than half, stating this is actually the the****utic value and was an error for the last 5 months. Convenient???? After 4 phone calls to the lack of service department, I was told on every occasion this is being investigated and I would be called back in the required working days. Not a call back from any of the calls made. Now to be told this is how it is, and there is nothing further they can assist with is just crazy, weeks later and I could have just saved my time calling for assistance. You pay for a premium service and get ******* when you actually need something. Sick....