I have Slingshot smart phone features and have discovered that the very useful feature called 'block unknown callers' which is very useful only works on numbers that have there caller ID blocked from within New Zealand.

This is sad they can't block international calls so it means I still get heaps of calls from scammers from asia phoning up to alert me to a virus issue with my computer or from global animal protection who want to do a survey about my full name, address, date of birth, place of birth, mother maiden name...

I phoned Slingshot and was told that can't do it but there system blocked 90% of unknown callers, which sounds great but is not the reality from my experience. I asked if I could block all international calls and was told that that was impossible too.

I find that very frustrating as the most annoying and criminal calls can't be blocked.

Any help of blocking these would be great.