The home that we moved into had a water filtration system which we kept maintained until We had our kitchen remodeled 2 years ago We had the under sink system removed due to lack of use and of room for it. Since then, we have received numerous phone calls (about every three months) and letters from them telling us that service is due on the system. We have told them that we don't have the system anymore and to stop calling us. Yesterday, we received a letter from them stating service is due. We sent them a letter today asking them to STOP annoying us. If this doesn't work, the next step is BBB.