Al Ahli Driving Center  -  transportation charges

I booked for pickup and drop services for my driving classes. Initially i was told AED350 where as in my account i was charges AED450. 7 days prior to commencing my driving classes I was told that first day i will have to come on my own so i asked them to cancel the pick and drop as Taxi was more convenient. Al AHLI driving school refused to cancel my pickup drop. I had made all the payment for my driving classes but had not paid till that time for the pick and drop but they threatened me that they will not give me driving classes and forced me to take pick and drop service. The pick and drop was 2 times costlier than taxi.
Is there any authority where i can file a complaint against them. Kindly advise on [protected]@yahoo.com