Who called from 2132866600

Follow up comment, We have a kall8.com account that messages and phone calls are forwarded to certain employees.

Also received call, no message.  Called the number back and received "not a working number" error.

Our company keeps getting calls from this number and no one is on the other end. When we try to call it back it says not a working number or it gives a busy tone. How can we fix this? We are a call center and its backing everything up.

Receiving calls 2-5-09 from this number over and over and no one is there.
Online directory look-up says it is out of Michigan.  We too are a call center and the number is backing up our primary switchboard and call center.

It's not coming from Michigan it is a landline in California.