Bad understanding of customer service.

When to Pick n Pay clothing at East rand retail park to exchange a clothing item that I purchased in the last week of December. The staff did not seem to understand the meaning of customer service as they wanted me to pay extra as the T-shirt I had purchased was now at a reduced price (R50) where as I had purchased it for R70 and the one I wanted to exchange it for cost R70. This would mean that I would have now spent R90 in total. This is not a huge amount but what frustrated me is that I was accused of *****ing the t-shirt and coming back to exchange it. I am very disappointed by this incident and don't believe I will be returning to that store. I ended up leaving my item at the store out of frustration. The manager they called in went by the name Mpho.