Age itself has nothing to do with it. There is still plenty of paper insulated, lead-sheathed cable from the 1920s & 1930s providing good service.
Deteriorated insulation SOMEWHERE is the cause of the noise on your line.
You should have promptly reported the trouble again. ...and again, if necessary. Then there's your state's Public Service Commission that will take your complaint if your carrier won't fix the trouble.
You're paying for good service. It's too bad that things have changed to the point where you MUST be your own advocate ("squeaky wheel") but it's a fact. Submit reports until the trouble is fixed.
That's pathetic. :(
New lines have nothing to do with it. CLEAN lines do. They replaced the old cable because the cost to maintain the old cable finally exceeded the cost of replacement. The old cable must have been beyond TERRIBLE for that to happen.
Lemme guess: You live in the country. I'll bet your "local" CATV provider is no where NEAR your home and may never be.
SBC certainly has plans to *EVENTUALLY* offer high-speed internet service in your area. They are simply deploying first closer to the Central Office (or remote terminal) than further away.
There is a smaller, unincorporated community in the area I service. They would LOVE to get DSL. We'll get there eventually. Understandably, it isn't SOON ENOUGH for them.
Even at the furthest distance from the C.0., you should get dial-up connections in the 26k range on a good pair. Give 'em hell, Harry.