I purchased a black & Decker BV4000 Type l l20Vac 60142 Blower and Vac from Home Depot a couple years ago and from day one the vac bag will not stay tightly attached and the debri blows all over operator and into air. You replaced this bag once, but now it is not working again. Have you improved this product and since the replacements aren't working, am I entitled to a discount on a better product?

Please advise as this is an excellent idea but a very bad designed product.