When it rains...

Whenever it rains, our phone line goes out for two to three days! I've tried calling Comcast several times - they've come out several times but no success there. I've called our area field tech several times. I'm unable to get a hold of him and the one time I have, he said he would fix the problem and call me back to let me know the status. He did not fix it and he did not call me back. Will I ever get this problem fixed? Or should I just switch back to Bellsouth?? We've been more than patient - this has been ongoing since February 1st.