Cash@Till

I went to boxer Trade Route today to purchase something, when I reached the till I paid and requested for cash back. The cashier had an attitude and said they don’t give out cash back of the amount I requested when I asked why she did not have an explanation instead she became rude and asked if she must continue with the amount she wants to give me. I would like to know from Boxers superstore’s what is your limit for cash@till and what would it take for customers to be treated with respect? It is really disheartening to experience such horrible customer Service.