As currently written you will be able to handle one customers account per run of the program. While that might be an appropriate initial step in the assignment, I presume that the final assignment will require that the user be able to enter more than one customer information per run of the program and that it can be terminated whenever the user wishes. If that assumption is correct, then looking at a control loop someplace would improve the program.
For Each ctrl As Control In Me.Controls("pnlMainPanel").Controls
If ctrl.GetType Is GetType(System.Windows.Forms.Panel) Then
For Each subCtrl As Control In ctrl.Controls
If subCtrl.GetType Is GetType(System.Windows.Forms.TextBox) Then
If subCtrl.GetType Is ...