Bad service

I took my vehicle a Chevrolet Utility Ldv to a local Service Centre specializing in the service and repair of Chevrolet, Opel and Isuzu vehicles. It took two days to get authorisation for the service as the service centre is not on the list of preferred service providers of the Innovation Group. When authorisation was eventually obtained it was only for an oil service. According to the policy document of the service plan it stated clearly that the services must be done according to the specifications of the manufacturer of the vehicle. As the service that has to be done is a 120 000km service, it entails much more according to the specifications of the manufacturer. Is this a case that the Innovation Group is not bound by the specifications of their own policies or is as a result of bad service by their staff. I feel that this not a fair business practice and need the attention of the Innovation group management.