Update my pension payment letter

I am one of the Compensation permanent pensioner and get paid via my bank account.In every year I use to ask the letter that comes from the office of Compensation that state as a witness that I'm receiving my payment of my disability for the rest of my life. I use to ask the letter for the sake of my financial background were I need their help, but since from last year I'd **** several calls from their call centre send emails but no one is responding