New Disposal

I called up the maintenance guys today because our sink has been having drainage issues (I have to continuously run the disposal for plain water to drain). After taking a look, they told me our disposal was way too old and that they would bring a new one! Hooray! Our disposal has never really worked, but I thought they would just do a temporary fix. Hooray for being able to put soggy cereal down the sink! (Yes, our disposal was that bad.) If I understood the tidbits I heard from them right, our disposal was nine years old, which I guess is pretty old. I noticed the one they put in claimed it would work for seven. I should have called a long time ago...