Response to Improper Billing After Payment

Dear

On / / I received your letter which indicated that I
had a balance owing in the amount of $

On / / I mailed a check to you in the amount of $
You should have received my check prior to writing your
letter and I am, therefore, somewhat concerned.

If you have not received my check by the time this letter
arrives, I would appreciate hearing from you inasmuch as I
should issue a stop payment on the funds.

I will hold this matter in abeyance until I hear from you.