i bought a tablet from tesco direct online. i paid for the tablet and collected it a few days later instore. a few weeks later i checked my bank account and noticed that tesco had refunded the money for the tablet in full. and i also had an email saying there was an error and it was not in stock therefore they were refunding the full amount of £398 to my account. Two months down the line i get a call from tesco CS asking if i had received the tablet which i said that i had. she then went on to say they had mistakenly refunded me the money. My question is, do i have to pay for the tablet again because of tesco's incompetance. im assuming that because i kept my part of the contract when i paid in the first place, i have fulfilled my legal obligation and they dont have any right to ask me for the money again, am i right or will get myself into trouble with the law?