Internet issues not resolved by technician - no attic work and no solution

Tech came out and said there was interference with my wifi.  He checked all three outlets then proceeded to tell me that comcast rules state he cannot go into my attic to check my wiring.  All three of my drops are interior to the house.  This makes no sense.  Your wifi is not good and the company that provides it will not fix it.  I asked for alternatives other than chaning carriers and he had no answer.  Why would this be acceptable customer service?  So if it's true that company policy will not allow techs in the attic then what is the solution?