ADT Solar Solar panels placed on barn (which is shaded), not house (which gets full sun); financial details misrepresented, minimal reduction in power bills + monthly payment for solar panels

My wife and I approached Sunpro Solar (later sold to ADT, prior to our installation) to add solar panels to our home. Our house gets full sun 6-8 hours/day. The salesman suggested putting the panels on our barn (it gets significant shade during the day) and we told him the barn is shaded, the house is not. He said the engineers wanted to use the barn and that we would get enough sun exposure to offset a significant portion of our electric bill (averages $450/mo). After some more back and forth, ADT won the argument and installed on the barn. We had to cut down one tree ($$$) to improve the sun exposure. Since installation (which took months to complete and involved our county not approving the original array and reducing the number of panels because they would "produce too much power"), our power bills have been lowered by a mere $20-$50/month, while paying $359./mo to the finance company with our loan. A bill review was requested, because we were promised an 80% reduction in monthly electric bills - ADT offered us a settlement amount of $249 (not per month, TOTAL) for the prior 13 months and wanted us to sign a contract restricting us from posting negative reviews online. ADT says they can't control the weather (of course not!), but the fact that they installed the array on a building which gets significant shade, despite us asking for them to use the house, AND promised an 80% reduction puts some responsibility on the company.