Woolworths Fruit is vrot (rotten)

This complaint is on behalf of my pensioner mom-in-law... She purchased a watermelon that turned out to bruised on the bottom and completely rotten inside. She called, and was put through to a manager at the Tyger valley branch, and was pretty much told that it isn't his problem, and that she should take it to her nearest Woolworths branch to swop it out. She explained that she is a pensioner and unable to drive, having been previously taken to the store by her son-in-law (me). The manager was unphased by her situation, even though the error clearly lies with Woolworths quality. The whole experience left her wondering if Woolworths should still be her store of choice given that we have a very nice revamped Checkers nearby.