It's been 10 years now, but I had a BIG problem with Medical Alert and their corporate parent, Connect America. My parents had had a Medical Alert system for several years, though they never had a reason to use it. Eventually they decided to move into an assisted living facility. I was living across the country at the time, but they had local nieces and nephews who helped with the move. Their house was to sit empty for several months, until I could get out there to help clean it out and get it listed for sale.
When I arrived, I found the Medical Alert system, unplugged, backup battery drained, and of course the phone line it had been connected to had been disconnected since my parents had moved months earlier.
Medical Alert CLAIMS to continuously monitor their hardware, and in case they detect any problem with the system they call local authorities to do a wellness check on the home occupants. Months went by, and that never happened. The system had been stone dead for months, and Medical Alert either couldn't tell, or didn't care. I shudder to think what would have happened had my parents actually had to rely on the system.
Adding insult to injury, when I packed up the hardware and shipped it back, delivery signature required, I was subsequently billed hundreds of dollars for the hardware I 'hadn't returned'. I provided a copy of the signature card proving the package was delivered, they told me the package was signed for, but I couldn't prove there was anything in it. They wouldn't claim there was nothing in the box, only that I couldn't prove that there was. That lead to a multi-month fight, in which the credit card company ultimately backed me, but it left a very bad taste in my mouth.