Just had a call from a guy on that number.  Sounded like an average cold-caller telesales type, couldn't easily handle me redirecting him from his script :-)  I straight out asked who they represent - after some beating about the bush, he came back with INTERNATIONAL BUSINESS ASSOCIATES.  

Same issues you all had, except, they showed up "unannounced" at our door saying they have an "appointment" with my boss.  My boss is in and out all the time, and had specifically told the guy to CALL FIRST (which he didn't) if he wanted to "stop by."  Then, when the guy finally left, he sat in his car for 15 minutes and then called again (using a different name)!  Since then, they call at least once a day and will not give me more info than "IPA."

Caller ID just says Auburn Hills 248-237-3496

Glad to see I'm not alone here. :)

I keep getting calls just like this too!   They refuse to leave a message and are quite rude.

I just called and told the receptionist to place us on the 'do not call' list.  Lets see if that works!   Does anyone know what kind of company this actually is???

The number is also local to our company.  First time she called, she asked what type of business she was calling, when I answered the questions she insisted she had confidential information for the business owner.  Called back 2 minutes later with the same schpeel.  Calling us again today.

this witch called to ask if we were an engineering company.  I said no and asked who she was and the said, 'i probably have the wrong number and hung up.'