[robhol]

The only two things I can comment with my limited Japanese skills actually have very little to do with grammar. My main "complaint" is that this conversation is badly structured.. Who's saying what, here? When imitating a conversation you don't go like
"Hello, oh, hello there! how are you? fine thank you"
because that's confusing and doesn't say much about who's saying what.

As a licensed nitpicker I also want to point out that you've written iPhone in two different ways, neither of which are correct. Small "i", capital "P".

For the grammar itself I'm afraid I can't really help, but I'd advise you to "clean up" and restructure the conversation a bit.