Don’t blame your ISP just yet, make sure you don’t have interference from other devices…such as in your home or other neighbors wi-fi routers. If so, this can make router reset the wi-fi signal or lock it up.
Next time you get booted, just logon to router and check the UP time, if you see the time reset, chances are high that you have another device interrupting your router.
In a crowded neighborhood, set your device to say Channel 1 / 20MHz. You may have to test other channels to find the right fit. Good luck!