Being harrassed by Ford Motor Credit, who do I complain to?

[BoomerD]

My wife used to get phone calls on her cell phone all the time, from people looking for the guy who had the number before her. Some fvcking deadbeat who ran up a bunch of credit with local businesses, allegedly for his ag business...
Tried everything, called the cops, (as some of the calls were for things like forged/fraudulent checks...no help, called Cingular several times, no help...
She finally gave up and changed her number.