Dissapointed

I went to Dobsonville Pep store to exchange shoes, I get to the cashier, she asked for the parcel tag where my goods had been placed I realised I had misplaced it somewhere in the shop luckily one of my friends was able to find it and she brought it to me by the cashier, with attitude she told me if I didn't find the tag she wouldn't exchange it for me, I just surpassed the comment and ignored her, she took the tag threw it at the table behind her and asked one of her colleagues to bring the goods in parcel counter 1, she asked for my address and telephone numbers also with attitude I provided her with the requested information, she then asked for a price tag for the shoes, I realised I somehow misplaced it, she went on how I am supposed to have the price tag so that the next customer can be able to purchase the shoes, and asked me how they supposed to purchase without a price tag, I politely asked her what should I do since I didn't have the price tag, OMG the cashier went ballistic and told me I should acknowledge I am wrong and I must beg her to exchange my goods, seriously I have my slip can a price tag really cause such a scene. Customer service is a core of every business!