Xfinity support - LAN line static - Need to talk to a human

Hello -

Trying to help my 86 year old parents, who don't use apps or chat, get help with getting rid of static on their LAN line, and they (nor I) can find any option to call and talk to a real human. They have been Xfinity customers for over 30 years.

What number can they or I call to reach a human? Don't want to schedule and pay for a service call if it isn't necessary. 

Here is the issue and details:

Issue:

They have a LAN line and there is a lot of static on all phones---2 corded phones and 1 base phone that also has 1 extension. Their phone with a base also has an answering machine (they don't want/know how to use Xfinity voicemail) and the caller hears a lot of static while the outgoing message is playing and my parents hear heavy static on the messages callers leave on it.

Details:

> It is a consistent, ongoing issue for every call.  Issue doesn't get worse when there is rainy weather.

>No problem with their Xfinity cable or internet connections.

> They have been in same house for over 30 yrs so wondering if it is worn/old lines.

> All lines in their neighborhood are buried in ground.

> They asked their neighbors if they have this issue but none of the neighbors have a LAN line.

I am not at their house right now to troubleshoot via a call but could be there to do that at a scheduled time. 

Please advise what to do or a phone # to call, or if I need to go in person to the Xfinity store to see a human. It is really hard for them to deal with this issue.

Thank you,

Andrea