You’ll need to call Sonos Support directly to discuss it, they’ll arrange any returns, if available.
For what it’s worth, most connection issues are caused by local network issues, between your controller and router, or the router and the speakers. I’d certainly check the wifi interference FAQ, as well as performing a Sonos network refresh, by unplugging your Sonos devices from power (or powering them off, if battery connected), and rebooting your router. Once the router has recovered, power back on your Sonos devices. This will give them both a fresh IP address, as well as a refresh of the Sonos OS. Finally, check your system for updates, in case there are any that need to be applied.
I have more than 20 devices, and haven’t experienced any issues.
As for a class action suit, there have been many requests, but not a single one has been filed, to my knowledge. If you feel the need, please seek out legal representation to file such, and be sure to show them the legal agreement you ‘signed’ to use Sonos equipment.