no customer services towards customers

I wanted to buy on sunday 21/06/2015 I had no store card I've left it at home, so they told me I cant without my card so I went back home to collect my card so that I can buy when I got I pick whatever I wanted went to the tills to make that purchase with my card they still told me I cant buy, so I asked what was wrong told me that I need to produce my iD my proof of address before I can use my store card I asked why, then told me to follow her to customer service is then they say my signatures are not the same. To my surprise no one asked me my personal questions to see if I was the write question. I am so sad as they treated me like a ********.