Received letter claiming I made an agreement...

Sounds good. Did you request a debt validation? If not you can request it in your letter. If you did, point out that there will be no settlement until they provide the validation you are entitled to.

i did not because it's been long past 30 days and i'm not sure they have to oblige

Go ahead and send it out anyways. You have a right to the information and if they cannot provide it you need to know that. However, I disagree with the statement about "there will be no settlement until I see it in writing". I would not add something like that because it may be interpreted as you admitting the debt is yours. And that can backfire on you later. I would just state that in accordance with the Fair Debt Collection Practices Act, you are hereby requesting full legal validation of this debt. In accordance with the fdcpa, also inform them that per section 809 of the FDCPA they are to cease any and all collection activity once they receive your request, until such time that they satisfy the request with proper validation.

CA's have done this before. I have received things like that before myself. It's a weak trick at best. It only works if you do not assert your rights under the law.

Thanks! here is my second draft ... i don't want to sound threatening or anything because i don't want them to sue me out of spite or such.

"I am writing in response to a letter dated January 21st, 2008 that I received yesterday, stating ???????This letter will confirm your agreement to remit a payment in the amount of $466.66 due in our office by 1/31/2008.???????
This is not correct. During this conversation I made no promise to pay any amount by any particular date. Please provide documentation to support this claim. I would also like to see a written validation of the whole debt amount per rights under the fdcpa law. Please forward me this information in writing."