recieving blocked calls from creditors

I think you should report this matter to the police since it is causing disturbance to you.

I would report it but how could they trace this information if they are calling blocked?

WHen I set up phone service at my house, I got the most up-to-date call blocking features available. Now I only receive calls from people that I know...like family, legitimat, un-blocked business, etc.
Look into it with your telephone service provider! It doesnt cost much!

Yes, this package will:
(1) Block --completely-- people that are trying to be deceitful
(2) Prompt the person to identify themselves before your phone even rings. If they refuse, your phone will never even ring. If they identify themselves, your phone rings distinctively and you can choose whether or not to accept the call.

If a normal call ever comes in that you don't recognize or appears to be "Blocked" or "Unknown" just don't answer it. My bank used to do it until I told them that I'll never answer the phone unless they manually unblock their number each time they call me (which they CAN do).

I live in the Baltimore/DC area which is the telemarketing capital of the world. And let me tell you, this service from the telephone company is well worth the extra $10/mo or whatever it is.

Filing a police report won't really do much (to the best of my knowledge) because there is no direct threat to your well-being and they will most likely tell you to contact the telephone company.

When you contact the telephone company they'll tell you "there is nothing we can do". It's pretty sad, yes, but it's much like the email spam situation: you just need to find a method that works for you to make it stop.