If you believe you have any reason to complain about the conduct of any driving instructor, or the driving school they are associated with, your first step is to read the driving school’s Terms and Conditions and complain to the driving school directly. A phone call might be enough to put things right for you, but if not, or if your complaint is particularly serious, you should write to the owner of the driving school at the address on their website, giving full details of the issue you are complaining about and what it is you want to put the matter right.
If you are still unhappy with the response you receive, you can write to:
The Register of ADIs
Driving Standards Agency
PO Box 280
Newcastle-Upon-Tyne
NE99 1FP
or you can telephone them on 0300 200 1122.