Refuse to exchange a jean due to a tag

I purchased a pair of jeans from this store, but unfortunately they were too small. While trying them on, the price tag accidentally fell off; I placed it in the bag immediately. Four days later, I returned to the store to exchange the item. The cashier informed me that because the tag was no longer attached, the jeans could not be exchanged. I explained that the tag fell off while fitting the item, but she stated it was a “new rule.” When I asked why this rule was not explained at the time of purchase, she dismissively rep**** that people wear items and return them, then walked away. This was extremely unprofessional and disappointing. Poor customer service and unclear policies like this are unacceptable. Based on this experience, JUMBO Graaff Reinet has been the worst store I’ve dealt with.