MacMall selling defective apple poducts, Internet

In Oct 10,2012 I purchased a 15 in mac pro rtn from MacMall upon receiving computer i installed some of my apps and software the following day i turn on the computer nothing dead , I check make sure the battery is charge everything on my part is done checked i decide to go online trouble shoot through apple still nothing dead computer is not working I call MacMall explain whats happening with my day old computer after a half an our they decide i need service they give me a tech. He is very helpful but still we him and I can not get the computer on. They give me an option to send it back and i do two weeks later they tell me that they are charging me $450.90 because i left my software on the computer . I tried to explain I could not turn the computer on . This is why I left all my personal information as well as apps software. The worst company I have ever dealt with . Why would anybody who is buying an apple product deal with this store .