Refactoring of the Program (Yes, again...) because of Code Smells

[EmilioSG23]

Hello, I'm doing a work about Code Smells and I see your repository again for it.
In addition to the previously reported, I see that your code in some parts isn't easy to maintain.
So how the previous report, I'll give you some advises to solve it.
First, I identified the following code smells: Switch Statement, Feature Envy, Comments.
Each smell can be refactorized with this techniques:
Switch Statement: You use Type Code in Account class and don't use polimorfism. I suggest use Replace Type Code with Subclass and Replace Conditional with Polymorphism.
Feature Envy: Customer class have a method that only use fields from Account class. Move method to Account class.
Comments: You use in some parts of the program comments. It isn't bad, but I suggested that don't use it for explain a part of the code. You can use Rename Method techniques, it'll be better for the performance of the program.
I hope to help with it. Thanks!