On PTS's main number they shut this one completely off yesterday. It's not a permanent shutoff. That's why you're not hearing any ringing at all, just silence. The talk channel is not even getting raised.
It's a mixed bag on the other numbers. I believe they are using different providers for the different numbers, probably based on cost. They have also programmed each number to behave differently.
Be sure to try all of the PTS numbers and the come back later if none of them are connecting. Like any Indian-based scammer, they will pop right back up as soon as you look away for too long and stop hitting them.
PTS is definitely of the size and income that they could pay bribes and they have a fairly strict company culture (this is why phone agents rarely lose their cool and act like robots). They strive to appear as genuine a company as they possibly can because this provides them protection from the authorities.