Atlantic Auto Mall of Long Island Rip off

I recently brought my 2000 hyundai tibiron in to the atlantic auto mall for service my engine light was on and the front end was shaking . my gas cap was missing and my front tires needed to be balanced . i received a call at work from the service department saying they already did the repairs and the balance was $95.05 for the work. Almost 100 dollars for a gas cap and 2 tires being balanced, without my consent, this is pure rip off. a cap cost about 10 dollars ,totally sickend by my bill i paid it and let them know i wouldnt be bringing my car back there for service and that it wasnt going to end there. Nina Lauria