Same experiences with pumps (not with stores)....
Take a look at this on Amazon. Can't post the url.
It works and cost (after the coupon) is less than the Joe Blow's we've both used.
Oasser Air Compressor Portable Mini Air Inflator Hand Held Tire Pump 2000mAh with Digital LCD LED Light 12V AC DC Lithium Battery 120PSI
Good luck...