Got several calls from this number. No message was left. Who are they?

It's the marketing person pushing NY Philharmonic tickets.  You ask them kindly not to call back but they do.

Calls every day and doesn't leave a message. Please stop or block this call going forward

This number kept calling me together with another similar no.
I can't find out who this ntumber is I don't even want to call back or pick up as its not in my phone list.
Anyway,just want to know who is this and want this number to stop calling.

calls almost every day and leaves no msg...a similar number that also calls a lot was from the nyc philharmonic, so I assume this is, too.  I've seen a show there before, but definitely don't enjoy all these calls!