Worse piece of clothing item to buy ever

Today my sister went to MR Price in the Golden Acre to exchanged two shirts. Note its the same just different colours. I hand washed it and hanged it out to dry. Once she put it on she found both of the shirts shrinked. This was explained to the cashier and she said \ No body else complained yet and we can't exchange it". Clearly here is a manufacturing fault and she denied a customer of service. She didn't even talk to the manager "