Very bad interest service and unresponsive customer service

For the last three days my interest has not been working properly. Some times it says connection without interent and there is a red light on my router that appears 4-5 times a day. I have sent three emails and phoned twice where no one answered my calls. No one from the customer service has answered any of my emails. I am very unhappy with the service since I have switched my plan from 4G to 5G, I have not had any problems with the wifi connection until now.