sidevalve
Über Member
I fail to see why they should take it back. There is no fault with the bike you bought it and now you have decided you don't like it. If they take it back they will have to shift a second hand bike and unless they told you it would fit they have done no wrong. It's like buying a car and taking it back a week later because you don't like the colour. Unless it's way too big there are as above loads of things to try.If it is too big then it is too big and no amount of faffing about with this and that will fix it. If you have only had the bike a few days then you are entitled to take it back and ask for refund. Of course they did a deal on it - they wanted to get rid of it
Shorter stem, raise / lower the bars, narrower bars and even change the type of bar. If the pain is in the shoulders I think it points to a bar / front end prob - try an adjustable stem and see if you can find a suitable position with that.