Why should he tell you what you should change to get approved? You already said that you had new ideas about how to differentiate your service against Upscribe - why not list these out into a roadmap? You've not offered anything that is different to one of their providers already offers.
At the moment, you're claiming that 'novelty' is the choice of consumers to choose a different product. That's not novelty, that's competition.
Their comments are entirely reasonable - submit it when it has something new to offer. You say that you have these ideas - and if you truly believed in what you were doing, then you would put this time in upfront on the product on the speculation that it would be so good, they could not turn you down.