Regarding basic pay protection.

I joined NTPC in 2021 at the E2 grade with a basic pay of ₹50,000, transitioning from my previous position as an Assistant Engineer at MPPGCL, where my basic pay was ₹69,000. At the time of joining NTPC, I signed an undertaking (as attached) that precluded me from seeking pay protection. This undertaking explicitly stated that no representation regarding enhancement of basic pay or other benefits, apart from those in the offer letter, would be maintainable.However, I was later promoted to the E3 grade in 2023 with a basic pay of ₹60,000. It has come to my notice that other candidates who joined NTPC directly at the E3 grade in 2023 were not required to sign any such undertaking and were granted pay protection after necessary approvals.I meet the eligibility criteria for pay protection as my basic pay in MPPGCL was ₹69,000. Despite this, I was denied pay protection due to the undertaking signed during my E2 selection. However, in 2023, candidates in similar situations were not subjected to the same requirement, nor was pay protection explicitly denied in their case. Please guide.