No service

My internet is out.
every day for a short time the internet shuts off and comes back in about 10-15 min. So no phone no TV no security system nothing is working that I pay for. First off we should get a rebate.
second— why does this happen

it never happened like this with Xfinity.
I am tired of trying to do work,

watch tv or use the phone tonight supposedly it’s off until 5-6 am