I find myself in the unenviable position of being on Facebook's side on this one. What's happening here is that telcos have found a new spin on trying to extort people in the way that their monopolies uniquely allow them to do so.
This is laid bare by Telefónica complaining about regulation. The existence of that regulation is basically the only reason we have the internet today. Without it telcos would happily destroy themselves and the market for their products by abusing the monopolies they're handed by governments even further.
None of us owe any of these telecom companies an extra dime. In many cases they owe us for not fulfilling their obligations in the one-sided agreements they get from governments to maintain monopolies. They owe us for the anti-trust behavior they openly admit to by carving up the access maps to avoid competing with one another.
This is probably one of the only situations where I'll say this: Facebook is doing nothing wrong here. Demonstrably worse companies are just hoping to make our lives a little worse by glomming on to the genuine hate-train going around for Facebook.