Charged for no work done on vehicle

Took my vehicle in for a diagnostic report on the 12th April 2018 and was quoted R960.00 for the job to be done. Later was contacted and advised that the vehicle would have to be stripped to determine the noise coming from the car, which will now cost me R2200.00 to investigate. I told them no to strip, just do the R960.00 normal diagnostic. Upon fetching my vehicle, i requested a report from the diagnostic but was told since vehicle was not stripped, no conclusive report could be made, was told it COULD BE gearbox flex plate. I felt that i donated the R960.00 to them since no report was handed to me to do a normal diagnostic, this was highly unprofessional since no actual work was done. I dealt with Solly Mahomed, After Sales Consultant from Zambezi Auto, who tried to explain why no report was available, to no avail.