Cognizant — Ex-Employee unable to get hike/revision letter

I am a former employee of cognizant.I have requested for payslips and revision Letter from [protected]@cognizant.com.They have sent payslips after long follow-ups.Now only saying that the revision letter can be given by seperate team and they do not know about SLA as well.

This is very bad experience woth cognizant.No prior intimation.Everyone will think after relieving from cognizant we can access external portal.But it is valid only for 3 years.No where it has been mentioned.After long search I found the mail contact even after that they respond very late.