Only cash notes

On Saturday 19/12/2015 I visited Max Motorsport with the intention of buying a car amplifier... When I arrived I spent about 10 minutes looking around until I found the item I wanted , I then waited for the sales agent to take my payment but I was told it is cash only ? I then noticed that most of the items in this store has a cash notes only sticker on them. I then had to leave and visit the only std bank arm in the area which was in umgeni center , being payday and festive season the queue at the atm was just crazy , this took about 20 minutes of my time. I then made my way back to Max Motorsport with the cash for the item and it took about another 10 minutes to served. My gripe is which sane person will walk around with cash in the middle of Umgeni road ? What is the purpose of this cash only policy in this day and age ? A transaction which should of taken about 10 minutes took more than 40 !!!