employee rights to a new pay plan?

Answer 1

Without more information, I can only assume what your problem is.

Unless you have a negotiated labor agreement specifically indicating the pay plan, an employer can change the pay plan whenever s/he so desires, provided that it is not done on a regular basis, or to cheat employees out of compensation due, or extends indefinitely.

For hourly employees, the pay period, generally, is weekly, at most every two weeks.

For salaried employees, the pay period is bi-monthly, or monthly in some cases.