From the Bills section, you can open a dispute on the bill you are working with.
Note:
You can open disputes only on bills that have money owed and that do not already have another open dispute.You cannot open or settle a dispute on a child account.
To dispute a bill:
On the account page, click the Bills tab.
In the Bills section, select the bill you want to work with.
To locate a bill, see "Finding a Bill".
From the Actions menu in the Bills section, select Dispute Bill.
The Dispute Bill dialog box appears.
For Dispute, enter the amount you want to dispute.
For Effective, select the date.
(Optional) Select Exclude taxes from the dispute.
From the list, select a reason.
(Optional) Enter a note.
Click OK.