Over the weekend this lady came up to me at my stall and started telling me that a bottle of wine she’d bought from me was off when she opened it. I genuinely didn’t know how to react. She’d bought it three weeks previously, opened it, tried it, thought it was corked, and then poured it down the sink. She bought me the empty bottle back and after a bit of to’ing and fro’ing I got the general gist that she wanted it replaced. How should I have reacted here?