Cognizant — Regarding Stipend

I joined Cognizant on 18 February 2022 as a Program Analyst Trainee. In offer letter it was clearly mentioned that we will get 12, 000/month. But after joining they told us that we will get stipend according to stage completion. And Rag score must be more than 70%. I full filled all the criteria but initially i got 5400, 10414, 8100 only. After that we are working but not getting stipend.
If we ask about stipend to any senior employees they are not responding.
Please do something sir