If you think you have been ripped off, take the registration number of the Taxi and report it to the Cyprus Tourist Organisation (CTO) office. The CTO, Police etc can and do take the taxi license away from the operator which will cost him/her a small fortune.
Watch out for the increasing number of un-licensed Taxis (must have a 'T' as the first letter of the 4 alpha 3 numeric registration plate to be legal) doing the rounds as they will rip you off or worse.