Cable

Three weeks ago I was upgraded to fiber. Since then one box has needed to be reset over 15 times. I go through the xfinity assistant troubleshooting each time. The box then work and the problem is resolved. Then it falls again. I have two boxes. The other has perforated flawlessly. I have asked for a technician appointment but the assistant program insists on going through the troubleshooting process again and again. How do I get a technician to just come out and replace this box?