I would like to change the home interface and dashboard I request communication with...

Several things, you can customize the home interface, be able to pin apps in the corner of the screen while playing, another simple feature I would like, is to change the position of the notification of unlocked achievements.

You can also check your Order History at account.microsoft.com under Payments & Billing tab at the top. From there, you can find the order in question and verify the ammount paid and method. Then underneath that order should be a link to "Get order help".
That will take you to a page that has further details on contacting the billing department and what can be done about the order.

For billing issues contact xbox support: (800) 469-9269 if you're in the US/Canada or
http://support.xbox.com/contact-us

Hi BoOsTeDBuLLeTz7. Since your Credits started pending after March 15th, they are scheduled to be deposited on April 12th. Thanks for your patience.

The request deposit button is only available when you have at least 1,000 credits pending but less than 5,000. It's just so you can have credits deposited before needing to have 5,000 pending first. Once you reach 5,000, they are automatically scheduled
to be deposited by the following 15th or 30th of the month. If you get to 5,000 between the 1st and 15th, they are deposited by the 30th. If you get to 5,000 between the 15th and 30th, they are deposited by the 15th of the next month.