I wasn't happy at first when they said they would reformat but like the girl said in store I have to give them a go at fixing the problem before they will refund.....
Actually you don't.
You are given the benefit of doubt BY LAW on any electronic product. They have t replace or refund within seven days, no questions, quibbles about it. The law assumes you are correct within that time frame, regardless of what they, the store think.
Try arguing it out with a shop floor drone though, it's a nightmare.