CSS Forums - Need help regarding Cadre Change in PCS

Salam Friends... I need help regarding Cadre Change in Pakistan Customs . I was Selected in 2016 as a Driver(BPS-04) in Pakistan Customs.. Due to Financial crisis I have only applied for this job. And By the Grace of Allah .. i Got Selected on purely Merit. I got posted in Custom Model Collectorate Multan with Additional Collector Office Duty. Here in Multan there is no professionalism and rules regarding duty timings.. I worked 24/7 Week... even my Sundays are went with officer... Once i said that to admin officer that this is wrong ... Sunday Holiday is my Right.. He threatened me.. That you are 24 hour worker.. we can call you anytime..even i havent receiving any performace allowance = Basic Salary .. So after struggling 1 year and 4 month.. I have decided to move an Application to senior officer of PCS.. about cadre change.. because one of my employee said to me that you can change your cadre from Driver to Dispatch Rider. Now i need your advice .. is it possible.. If yes... Then What is the procedure.?