the Department of Revenue and Taxation chooses to enter into contracts with temporary income tax returns processors, the Department of Revenue and Taxation shall promulgate rules and regulations governing the contract. The processors under contracts shall be deemed independent contractors and not employees of the government of Guam, nor shall they be entitled to any benefits otherwise available to government of Guam employees, including, but not limited to, sick leave, annual leave, retirement, worker’s compensation, group life insurance, group medical insurance, or periodic or other step increases in wages.