In a call center language is your main working tool. It has to be near-perfect. My experience communicating with a such "offshore call-center" was always less than subpar. And I'm not a native speaker either.

And yet you have a foreign web developer who'd be better at waving hands than speaking English, and somehow nobody bats an eye. The web page looks great, so here's a round of applause for our jorgi, who can't even phrase a "thank you" back.

Oh, and to bring the point back. Nowhere in Europe will you have non-native speakers working in a call center. Rare, very rare exceptions. And those all will speak their target language borderline perfect.