Need Help responding to form letter after first request

[azcolons]

I used the online dispute system for Experian and TU to request a 30 day late to be removed. After 7 days I received a form letter from TU stating he following:

"Re: Verification Documents not Available

We store information on our records as it is supplied to us by creditors. When information is disputed, we are required to investigate and record the current status of the information. We do not provide dispute verification responses received from creditors. If you need to obtain documentation or written verification concerning your accounts, then please contact your creditors directly."

At this point in time how long do I need to wait before responding? How should I respond to this form letter? I do not have certified letter or envelopes to copy since it was done online, How should I proceed?

Thanks,

azcolons