We bought the Hoover Windtunnel vacuum just 2 1/2 years ago. Since then the switch had gone bad. I cannot get a replacement switch - they now only sell the ENTIRE handle with a newly designed switch for this vacuum. In the last 9 months it has developed an annoying growl that cannot be attributed to the belt or filters as those have been changed. It does not stay on because of the switch. The filter on the front of the vacuum that is labled as a Hepa filter does not collect any dirt or even seem to have any air flowing through it anywhere. In fact if you take off the Hepa filter you will see that...