Worse customer experience

I went to collect my online order from Ackermans Grahamstown high street store. On receipt of the order i immediately told the lady i would like a return for an exchange on the items she asked if i have the invoice i said i have it on my phone and that was fine. I spent about 45 minutes in the queue and when i got to the till point i was told i need to bring a printed invoice. I was told to go and print out the invoice after waiting for 45 minutes and i had asked what i need for a refund. I am not happy at all with the service at Ackermans long queues and less cashiers at till point and the staff not giving correct information to customers