Bad Entrance Facilities

We have been having an issue for roughly 6-7 years at our business location. We have submitted many repair tickets and continue to struggle with the same issue. Whenever it rains enough to saturate the ground, we get a high pitch static noise on the lines. Sometimes it resolves if the ground dries up, but often we open a ticket and a tech comes out who checks the outside box and says it's our side of the wiring. The problem is fixed temporarily and then starts up again when we get another downpour.

We are losing business when this happens. Obviously, when a customer calls in and hears this awful static they just decide to hang up. Maybe try again but we're certain many don't even try to call back.

We have been told by a few people who have a better understanding of the industry (Telecom) that it sounds like "Bad Entrance Facilities". We're having trouble understanding how to go about getting better support from AT&T on this issue rather than this endless cycle of dispatching and temporarily fixing. As a customer for this long it seems like it would be in their best interest to preserve this relationship and fix the root of the issue. I'm just curious if this all sounds accurate - bad entrance facilities? Rain possibly having an effect on our issue? Could it be faulty wiring or conduit that is leading up to the building's phone box and each time we're just getting a temporary "band aid" fix? Which is what it sounds like to me. Has anyone else experienced this, and how was it handled? Any suggestions, feedback, etc is much appreciated!