All persons engaged in the taxicab business in the municipality operating under the provisions of this chapter shall render a comprehensive taxicab service to the public desiring to use taxicabs. Holders of certificates of public convenience and necessity shall maintain a central place of business for the purpose of receiving calls and dispatching cabs. They shall answer all calls received by them for services inside the corporate limits of the municipality, as soon as they can do so and if such services cannot be rendered within a reasonable time they shall notify the prospective passengers how long it will be before the call can be answered and give the reason therefor. Any holder who refuses to accept a call anywhere in the corporate limits of the municipality, at any time when such holder has available cabs, or who fails or refuses to give comprehensive taxicab service, shall be deemed a violator of this chapter and the certificate granted to such holder shall be revoked at the discretion of the Legislative Authority.