Momentum Health not Paying Valid Claims!!!

On 16/03/2016 I received a letter from Momentum Health stating that I've been pre-authorized for the Flu Vaccine seeing that I'm at greater risk of contracting the Flu Virus. The letter also states that the vaccination will be covered under the Health Platform Benefit and that the doctors's consultation covered under my day to day benefit. They also mentioned the following: "All you need to do is ensure that you have your vaccination" and the letter was signed by Toni van den Bergh. On 18/04/2016 I went to my GP for my chronic prescription to be renewed and to receive this pre-authorized Flu Vaccine. This claim for the pre-authorized flu vaccination has now been rejected by Momentum Health stating that this medicine is not covered by the scheme. Today 04/05/2016 I contacted Momentum Health and spoke to Jason regarding this matter. He had all type of excuses why this claim was not paid and that I must sort it out with my GP. Earlier in this month they also tried to get out of a claim for a blood test that is covered under my authorized chronic conditions! Is this really the type of service that you can expect from a "World Class" Company????