Bad customers service from Woolworths Cashiers

I am so tired of bad service !Why sell premium products without the service to match it. Last year, I had a complaint from a cashier at Woolworths on Kerk Steet, Johannesburg, and this was never resolved. In the last few weeks, I've had two awful encounters from one particular lady at Woolworths on Harrison and Main, in Johannesburg. I'm starting to not see the point of supporting a business that disrespects its customers.