It's always a bit tough to be hard on a shop for supplying the wrong arrows; when you go to a shop and have your draw length measured, arrows are supplied based on that and usually adding a bit for safety for new archers. Also that's based on arrow charts that don't account for the speed of various limbs only the draw weight. Then back at the club, weird stuff like coaching happens, draw lengths change, people cut arrows down, massive fletches are added without a thought for clearance, and all that, and suddenly the local shop are a set of bastards for giving me the wrong arrows... I've heard archers who have been shooting for 5 minutes saying how such and such shop gave them the wrong arrows because they're going left and they must be stiff, then you watch their release...
You can't expect a shop to do the hard work of matching arrows to your bow for you. Ball-park yes, any further, definitely not.
I'd be looking for someone with a similar draw length as me in the club (unless you are actually like me at the frustratingly long end) and asking what arrows they may have in their locker that you could try. And for a bow, service and knowledge, see Alan at Merlin at Bishop Auckland.