Home Phone Cutting Out

[Edit: Formatting] The sound cuts out so that the other party cannot hear me, though I can hear them. At first it was only occasional. Now it is with every call. Sometimes I can talk for 15 minutes before the trouble starts. Sometimes it starts right away and is relentless. Then I have had to tell people I will call back on my cell.  I tried plugging my wireless base int the modem to bypass my wiring. It did not help. I tried plugging an old fashioned handset directly into the modem. It might have been better but still cut out several times in one call. 

I am dreading going through the usual customer service process, starting with the Asia based call center reps, and moving through the system and diffent service reps to a home visit. But at least I hoped I could look forward to an eventual fix. But the posts on this forum are a bit discouraging. I hope the issue has gotten more attention since the earlier posts 3 months ago.