Hi there, I would not have accepted the arrows if they were not what you wanted or asked for. As for the shop giving you something other than what you wanted, well I would not go back. As for shooting helical vs. straight fletch. Helical is better.The problem you are probably having is that your fletching is hitting your rest. You must be 100% sure that your fletching will clear cleanly. Check your arrows and see if your knocks can be turned.