My parents are making me use this otterbox defender case for my iphone 3gs. It makes my phone look bulky and fat and it can barely fit in my pocket. I kept trying to ask them to get me a different case but they said no and if i keep asking they will return the iphone. They want me to use the otter box because the sales person at bestbuy sais the iphone can't break at all with this case on.How can i convince them to let me get a different case for my iphone 3gs? please answer