No cover

I am the owner of a Hyundai Veloster which is currently on a 5 year motor plan including top up cover. To my knowledge my car is completely covered and was bought less than a year ago. I brought my car into your Hyundai dealership today regarding a faulty aircon. Upon diagnostics, the aircon was shown to be fine and without fault. I was advised to bring it back when it acts up again. I was however charged R610.00 for running the diagnostic test and my car would not be released to me without me paying this amount. The only reason I did not go to the branch at which this car was bought was because the Garsfontein branch was more convenient. Hyundai Roodepoort advised me that I was not supposed to have been charged because of my motor plan and additional cover. Please advise as to why I was charged this amount given all my cover?<br> <br>