We are sorry for any inconvenience the recent shipping error may have caused you. Your shipment has been corrected and shipped to you this morning. I have also enclosed a shipping label for you to return the items that weren't part of your order.
I'm sending an...
Dear (recipient's name),
We are sorry for any inconvenience the recent shipping error may have caused you. Your shipment has been corrected and shipped to you this morning. I have also enclosed a shipping label for you to return the items that weren't part of your order.
I'm sending an updated bill with your new balance reflected. Please feel free to pay the remaining balance on your next billing cycle. We do try to keep mistakes to a minimum and appreciate your patience as we've worked through this issue.
Sincerely,
(your name)