NESCO VS-12, Deluxe Vacuum Sealer with Bag Starter Kit and Viewing Lid, Compact Design, Silver

I vacuumed bananas, apples and meat on the first day (with breaks between operations) and, although they seemed well vacuumed, the next day all the packages had air. The meat went to the freezer and the packages remained as long as the appliance emptied them (no too much). The next day I used other bags left from my old Foodsaver (they were checked as good) and I resumed emptying the fruit, Everything looks good until the next day when the air was in all 7 bags, I found that the bananas they had cheated in contact with the air, becoming black and with a horrible taste (they had quickly entered biodegradation). Also, on the second day the time for vacuuming was shortened from 5 seconds (in the first operations) to 3-2 seconds. My conclusion is that it is not the bags that are the cause but the sealing of the appliance is not perfect and the timer assigned for the sealing operation does not work correctly. I request a full refund because the product does not work in the parameters described by the seller.