I just used BOGO at the London West India Quay. The front desk guy was completely clueless. He disappeared into a back room and came back after 5 or 6 minutes. He said no one knew what to do with it, but they'd keep it and get a manager to fix it in the morning. Well, the next morning I received a call and was asked where the original certificate was. I said, they don't send the little books out to me, the website says to print this out and present it as the certificate. He could read it right there on the printout I'd given to the clerk the night before. Ultimately, the accepted it, but it is an inconvenience to be questioned and badgered about these things. They should train their staff better.