Each telephone company, as defined in section 16-1, and each certified telecommunications provider, as defined in said section 16-1, shall clearly and conspicuously disclose, in writing, to customers, upon subscription and annually thereafter, (1) whether the removal or change in any telecommunications service will result in the loss of a discount or other change in the rate charged for any telecommunications service subscribed to or used by the customer; and (2) for any promotional offering filed on and after October 1, 2002, with the Public Utilities Regulatory Authority pursuant to subsection (e) of section 16-247f, that the offering is a promotion and will be in effect for a limited period of time.