Firstly kyle did the cab have a taxi meter installed?. If so was the meter being used by the driver, ie was it switched on?.
If a taxi does a journey starting and finishing,in his licensed area then he must use his taxi meter for the journey.If the journey is finishing outwith his area then it is "fare by agreement"and the cost must be agreed with the hirer prior to commencing the journey.
If you booked through a company then they will have details of the journey in their office,these details must be kept for a period of at least six months.
How did you get the taxi driver's mobile no.?
Are you absolutely sure you booked a taxi and not a private hire car, there being a huge difference in the laws applying to each.
I would take any estimate of possible costs from the internet with a large pinch of salt.
Yes you can certainly complain to the licensing authority involved.I certainly would.
If i can assist you any further then please let me know.