Sassa makes an old man cry for his grant

My dad had being collecting old age grant for the passed 10 years.This month he did not receive a grant. He call the sassa office and they advised that he is receiving another income and his grant will be canceled.my dad doesnt receive any other income. The only money that is put in his account is assistance from my both sisters to help him pay for his utilities and buy food.So Im not sure why was it canceled. Another way for government to ***** from their people.