Bad service

I bought a body warmer Ackermans on Friday unfortunately it didn't fit my my daughter it and was the last item when I bought it so today I went to the store wanting the refund I was told to wait for the person who will do the authorization I waited for 15 minutes because i was told that she went to the pharmacy. when she came she told they can help me cause I don't have a receipt I asked her nicely that she do a reprint for but she refused after waiting for so long im so angry coz when I came I told the cashier I that I lost the slip but still she made me wait I'm disappointed with this service