So apparently credit bureas have 30 days to respond to a dispute letter, but first of all, I didn't send the letter by certified mail, and do not know exactly when they received it. Second, It's been 33 days and I have not heard back from them. Do they have 30 days EXACTLY or a little lee way..and since I forgot the certified mail, is there any way I can determine how long they have to get back to me?