"stack-n-vac" Space Making Storage System

My husband and I purchased 3 of these for our upcoming move. When they arrived we decided to pack one of the bags ahead of time to see how it worked. We were able to fit a lot of items in the bag- bedding, pillows, etc., but to close the bag you have to zip it using a plastic piece that comes off very easily and does not zip the bag well. After re attaching the piece 3 times and going over the zipped part we finally got it to close. We had no problem using our vacuum attachment to suction the air out of the bag. It did decrease the size by about 1/2. Then the directions state to close/lock the valve shut after suctioning the air, which we did. Everything looked great until the next day when the air had seeped back in. We attempted it on another of the bags and the same thing happened. The product is cheaply made and will not keep air out of the bag as advertised. Don't waste your money!