Providing these water quality things are fine there is the chance that the cord running to the disposal has developed a short or a wire has become disconnected. You will need to disassemble the unit to verify all wires remain securely fastened. The last conclusion is that the motor has burned out, in which case you will need to replace the disposal unit.
The wax ring is used to seal the drain outlet on the bottom of the toilet to the drain opening in the floor. When a toilet is installed, the ring is placed onto the drain... the toilet is dropped onto the ring... and the toilet bolts (also known as closet bolts) are tightened enough to lock the toilet in place. If that wax gasket ring starts to fail or isn't seated properly? Sewer gasses can sneak out from under your toilet causing your bathroom to have that suspicious smell. It can also cause water line repair to escape, sometimes invisibly, with each flush potentially damaging the floor hidden under the toilet.
If you bought the same unit it should line right up, if you were unable, you will need to remove or add length to the existing piping. This may require you to splice together copper with plastic, don't let this scare you the hardware store will have all of the necessary parts.
Sales representatives must know beforehand that almost all the answers above need to be encouraging. Otherwise, there is a slim to none chance a sale is made. Besides cold call prospecting, so much of the typical sales rep's time is spent trying to make sales when a sales situation does not truly exist.
Keep an eye on any leaks in and around the house. Inspect taps, pipes and your roof regularly. Watch for leaks and if you find them, get it water line repair as soon as possible.
Plumbers, contractors, landscapers, and related professionals are often indexed by numerous online websites eager for you to visit their "directory". Each field will have their own group of websites competing for your attention. In the end these "Plumbers Directories" are often incomplete, and frequently provide little more information than the phone book.
Over the counter drain cleaning products offer convenience and effective results. However, they are best left to those who need to simply improve the flow of water, not those who need to repair it.