Though i understand that it is inconvenient for people especially from village background to fill the forms/slips in English/Hindi,it is also true that may 90% of the bank staffs especially in govt. banks are locals who are fluent in Kannada and can help these people.This imposition of Hindi is more of a political cause,as long as your mother tongue is Kannada and people in your house converse in Kannada no one impose Hindi on you.You guys should feel proud that you make an effort to preserve your language.
On contrary most of people from North while talking to each other in a town like Bangalore will always start their conversation in English despite knowing fully that the person on other side is from North just because they don't want to seen as "Gaoti"(Villager) type .I don't know where we should go and cry about English imposition