Hi Al.
Honestly, your Rifle dealer sounds like a right twart.
If you had it in July, it must still be under warrenty.
Top of the range, or lower end, what they sell should be fit for purpose.
Sound's like you have been more than co-operative waiting for them to rectify the fault.
TELL them, its not fit for purpose, you either want a refund on the spot,or a new rifle, and dont take no for an answer, the law is on your side.
If he was worth his salt, he would have already offered you that option, instead of making rediculous excuses.
Good luck with it mate.
Bil