If you have made arrangements then they have no right to call you. If they persist tell them you are requesting a cease and desist and you want all correspondence done in writing. By law they have to honor your request.
You owe it, and they're simply trying to get paid. Make the payment as soon as you can to resolve the issue. The calls should stop upon payment you missed.
make sure it is in the system and they can see it and it has been approved. if they continue to call you can always send a cease and desist letter and call them on your own time.
Yes whenever you miss one payment the bank people keep on calling and harassing. It is better for you to go to the bank personally and tell your problem saying that you will pay it immediately as soon as you have the funds.