AN ACT PROVIDING FOR AN ADDITIONAL SEPARATION BENEFITS TO MEMBERS OF THE GOVERNMENT SERVICE INSURANCE SYSTEM (GSIS) WHO OPT TO RESIGN OR RETIRE BEFORE THE MATURITY OF THEIR INSURANCE POLICY THROUGH REFUND OF INSURANCE PREMIUMS PAID INCLUSIVE OF GOVERNMENT SHARE, AMENDING FOR THE PURPOSE REPUBLIC ACT NO. 8291, OTHERWISE KNOWN AS THE 'GSIS ACT OF 1997' AND FOR OTHER PURPOSES