Bad service

Today (on the 2nd of November, 2015). I went to Hypersave at Mankweng. I told the lady (Cashier - Lethabo), I need R12 vodacom airtime, R10 Mtn airtime and a bottle of water. Instead she took the wrong order an gave me 2x R10 Mtn airtime plus R12 voda. When I told her, she refused to rectify the mistake and just said its not her problem with bad attitude &amp