a very small direct debit came out the bank today for the first payment of my insurance so i called my them to find they have taken 75% off my years premium and said i was the one who is mistaken, didnt want the suprise of a massive bill at the end of the year so wanted to sort it out, but they were having none of it, just wandering that because ive brought it to there attention and they said numerous times the amount im paying is correct can they change there mind later on once they realise the mistake theyve made?