We had a buy one get the 2nd item half price voucher to use. The shop assistant had also told us about the offer not knowing that we had a voucher. She was very lovely and obviously trying to make a sale then when we came to purchase the items she asked us for the voucher as if she was going to challenge us for the discount even though she had told us about it without mention of needing a voucher to start with. Once she had her sale she wasn't nearly as friendly.