I will NOT put up with abusive callers to my landline or mobile.
They're INVADING my privacy. Wasting my time.
So I just hang up on them.
If a Charity phones wanting to sell a ticket, I just politely say 'no thank you, & please remove this number from your list'.
Indian call centres' are a right PIA!
Don't often get them as I on DNC Govt Register, but if my phone rings about Dinner time, I just pick it up, say NOTHING, & when an Indian voice is heard saying 'hello, hello', I just place the receiver back on its' holder. End of.