We recognize that defendants' interpretation of the statute has the virtue of ease of administration and calculation. However, convenience cannot override clear statutory language. Moreover, we are required to construe the statute in a manner which gives effect to all its words. Section 1 of Act 299 was amended to clarify that providers of telecommunication services, only some of whose services are now subject to regulation, remain subject to assessments under Act 299. The Legislature did not amend 2 to provide that assessments against providers of telecommunication services should be based on gross revenues derived from regulated intrastate operations.
Plaintiffs therefore contend that they are entitled to refunds.
Defendants argue that under the circumstances, our holding that 2 has been misinterpreted should apply prospectively only. We agree with defendants. Although the statute prescribes the remedy, retroactive application of a decision and the appropriate remedy are separate issues. Prospective application is preferred when overruling an established precedent or when deciding an issue of first impression whose resolution was not clearly foreshadowed. Prospective application is appropriate here because 2 has been consistently interpreted for over 20 years in a manner which we now hold to be erroneous.