No response to information request

I've raised a concern with Ramona (Service agent) about lack of information, failure to provide a copy of the job card i signed and Merc's failure to notice that a fuse for the vehicle radio was missing. She has not provided the requested documentation and has not called back despite an undertaking to do so within an hour. Trying to contact Customer Service Officer Palesa results in me holding on until the phone call drops. Where's the service???