Got refused buying 20 boxes of chocolates in Tesco a few years ago,they had loads of boxes, but got told the reason was i may sell them on and make a profit, or wait till the price went up and bring them back and make a profit.
They failed to understand as it was Christmas they where for my Dad to give out as presents to his care home staff.
Went back a few weeks latter and picked up 10 boxes of each type of sweet, and loads of other things,at a very busy time,put them all on the conveyor,big queue behind, and she said i couldnt buy more than a few of each,so left the whole lot on the belt and in the trolley and walked out.
Not many happy shoppers behind me though.