Then they shouldn't mind if there is legislation that enforces this
If they fight such legislation, and claim it is "costly regulation", then they should be asked "how can it cost you anything to not do something you have just promised us you would not do"? There's no way they could fight this, and without the telco lobbyists fighting it there's no reason why congress shouldn't pass it without delay.
If congress doesn't pass it, I'll suspect that not only are the telcos lying, but the congressmen who take money from their lobbyists KNOW they are lying.