[adpiucf]

There is no such thing as disaffiliation from your chapter unless you have transferred schools and transferred into another chapter. You can resign your membership, meaning you will no longer be a sister.

It sounds like you are very unhappy with your membership, so I would suggest that you submit a very brief letter of resignation to the chapter leadership, signed and dated. Make sure to return your sorority badge and any other sorority memorabilia, shirts, etc., to the sorority, as you will no longer be a member and are not entitled to own or wear letters.

If you have genuinely overpaid and are not getting anywhere with the officers regarding having the amounts credited, talk to the chapter adviser. You should have an exact accounting of what you paid and what you believe you overpaid.