I’ve been trying to find a phone number for Citi’s Credit Bureau Disputes department, but every customer service rep or supervisor I end up speaking to tells me that they can only be contacted in writing. No one I talk to has a phone number for them; the people I’ve talked to say even they only communicate to them by paper. I’ve been given a fax number of 800 274 7058 and a mailing address of:
Credit Bureau Disputes
PO Box 689100
Des Moines, IA
I figure, there must be a physical office, at a physical location, with physical people, who have phones at their desks! But what is the phone number that will let me speak to someone who makes decisions?

You’re better off sending the dispute in writing via certified mail with return receipt.
Almost all call centers have been outsourced to foreign nations and if you do manage to get a real person through Citi you’ll just get an outsourced clerk who will read from a script in response to any question you have
If they will not get you a phone number, then, even if you call them, they will either hang up on you or tell you to send a letter. They will not address any of your concerns. If their number is not disclosed to the public, then they are allowed to use the phone only for calls that they place, for internal calls, for calls from other businesses, and possibly for personal calls. If their number is secret, then the persons that you are trying to call do not accept calls from customers.