I am a pensioner and my account is in a PSU bank. They have withheld some money in my account withou

I am a pensioner and my account is in a PSU bank. They have withheld some money in my account without any sort of communication. I have sent an email to the branch. They called me and told that excess pension is being drawn (The 20% increase in pension when the pensioner's age is 80 years is reported as drawn when i am 78).

Looks like they are not aware of the concordance table and the OM that was issued i Jan 2013 that addressed to the issues pertaining to the pre 2006 and pre- 1996 pensioners like me. My query is whether the branch can hold money in my account without notice and without giving me copies of the documents that they relied on in coming to the conclusion. Can I sue the bank as well as the persons involved in this matter as I need to put in unnecessary effort to prove them wrong. Kindly let me know the laws that are relevant to me including any free links to download them.