Unetchial insurers

Since when does an insurance company deduct pro rate premiums the month prior to a policy's anniversary. Discovery insurance is this how you go about robbing clients of their money by deducting money from their accounts with no valid reason.My plicy anniversary is at the beginning of May however discovery goes and deduct R363.12 extra and then has the nerve to tell me that the extra deducted was for pro rata and that i am only due a R210-00 refund.