I need to block a number from calling me (on my sanyo katana) is there a setting in my phone or do i have to call my provider?

Hi, on this make and model it is not possible to set up call barring the phone has not got the software to do this, some newer phones can offer this feature but most dont.
the only chance you have got of getting a number barred is by calling your service provider and tell them you keep getting nuisance calls from the number you want banned and tell them to block all calls from this person.

as your phone does not have the software for call barring then this is the only way of blocking a number, you need to call your service provider as they can block it for you, but you need to tell them its a nuisance caller and you want them barred from calling your number.

hope that is some help to you