Querry regarding beneficiary enrollment in HIS

Last year i had removed my mother's from the beneficiary list of HIS but this year again they have added her name without my consent or any action even i was not aware of this.. i just got to know about this when I opened HIS portal to submit a claim. I have sent mail to them but there has been no response from past 3 weeks after 3 to Follow ups.. what should I do next? I am okay if they don't remove her name but I want to know how they added her without my knowledge.