800-841-1154

This number called me 5 times this morning, every 15 minutes they would call back.  They left an automatic voice message on my phone and a woman only stated her name as "Theresa Nesbit" (difficult to make out the name), then the automatic voice continued telling me to press one number to speak to a representative, press another number to call back at a later time, and press another number to cancel the calls all together.  Hopefully it wasn't fraudulent or charged money for picking up the call.  They stated a business at the beginning, but I couldn't make out the company name.

This is Ameren IP's customer service call back number.  When you call their customer service department, and they have a lot of calls backed up, they schedule a call back for you, and this is the number they call you back from.