The best way to document your interractions with WaMu/Chase is to record the calls you make to them. You can do this with a simple telephone recorder like this one from Amazon.com or this one from Radio Shack which allows you to use any recording device you already have that has a mic input (preferably voice activated). Both devices plug into your telephone line directly.

It is important however that you are aware of the laws on recording conversations. Federal law allows you to record any conversation you are a part of but some states require the consent of both (or all) parties in order for the recording to be legal. The following are two party consent states:

* California
* Connecticut
* Florida
* Illinois
* Maryland
* Massachusetts
* Michigan
* Montana
* Nevada
* New Hampshire
* Pennsylvania
* Washington  

The FCC defines acceptable consent as:

* Verbal or written consent given before the recording is made.
* Verbal notification before the recording is made. (This is the most common)
* An audible beep tone repeated at regular intervals during the course of the call.  

It would seem to me that writing to WaMu now to inform them that any conversations with you will be taped by you might be the easiest way to satisfy this. I would suggest sending it registered mail or at least delivery confirmation so you can prove that you sent it.

Recording all your calls with WaMu or Chase may be your best bet to prove you have been wronged if your credit gets screwed up or you are charged fees because of something THEY did.

For more information please see the following Wikipedia and FCC pages:

http://en.wikipedia.org/wiki/Telephone_tapping
http://en.wikipedia.org/wiki/Telephone_recording_laws
http://www.fcc.gov/cgb/consumerfacts/recordcalls.html

Please note: this is not intended to be a definitive guide to the legal intracies of wire tapping law. Do not rely on this simple guide to insure that your ass is covered.