Overcharging and deducting from my credit card

Overcharged me for ride. Took wait and save option. Charged more thM quoted and even higher than the normal option. The return fare i paid 50% cheaper than the fair Charged. Help desk just told me that the fair i was Charged is justified. They refused to call me . There is no way of contacting them . Telephone line cancelled. They abusing the access to my crefit card. They cannot be trusted.