manager at whiterose store

Been and collected my parcel from this store (great service from ordering online and pick up next day even at this time of year.) On way out saw some I candy headphones priced up at £15 buy one get one free. So take them to till to be changed £30. Told the girl she got the manager. Manager said no its £15 each. So I said you can clearly see both labels.the £15 one and the buy one get one free. She said no its been marked up wrong and wouldnt honour the labels. This is the second time something like this as happened to me in this shop. so I said you got to honour it. It clearly states it on the item. So she relpys in a cocky tone No I dont I will just remove from shoefloor. Like I said its the second time I have had this with prices in the store. Its not my fault your staff cant price up properly. Then to top it of you see people stood doing nowt and ask tgem too get a pair of trainers for you to be told no I cant do that im not off the trainer deptment. Total joke this shop.