I personally do not think reprimanding India will solve this. If somehow India stops this the void will be filled by scammers from some other country.
This calls for reforms in telecommunications systems / regulations / norms / protocols.
As if those would-be scammers in other countries presently don't scam.. because Indians do? How do Indians presently scamming stop would-be scammers in other countries from doing the same? That's nonsensical.
Face the facts, this is an India problem. Harsh economic sanctions against India are necessary to solve this problem, and if that fails, null routing India and the whole of South Asia if necessary. And if diplomacy fails, escalation to military strikes against Indian telecom infrastructure would be in order.
The fact that we haven't really seen anything near the level of Indian call centres tells me that this is unlikely.
I'm not saying that scammers don't exist in other countries, but that it's very rare to see anything with the level of sophistication and organisation that we see in India.