Intermittent Internet Connection

For the last 3 weeks or so I've experienced my WiFi connection drop multiple times per day. I've called the support line 3 times, each time they said they found some issue with my router and ensured to me that this wouldn't happen again. After I called the 3rd time, they sent a technician out to check my signal, who said everything was good, and my connection dropped not 15 minutes after they had left. Every time my WiFi drops, all of my wired connections do not lose connection. Please someone help.