Our closest one is a tesco extra. They had it a week and a half ago (I got the last two off the shelf), but they haven't had it back in since and there is just a big gap in the shelves and a label saying temporarily out of stock; same in another four smaller tesco that I tried. customer services couldn't tell me when they would be getting it in again
I've sent an email to the manufacturer as there doesn't appear to be any other stockist.
I'm pretty sure it'll be a case of them not realising just how popular it would be and not being able to keep up with orders.
I've had an email from Genius so thought I'd share
"Dear Mrs Lackadaisycal
We are sorry to hear you are having such trouble getting hold of Genius bread. We can assure you that there are no issues with supply as we are meeting all daily orders from Tesco. Unfortunately, we have found availability to be an issue in some stores but we hope this will improve with the measures we are taking to resolve these out of stock situations. Please do ask at the customer services desk if your local store has run out - then they'll know that you want it. Perhaps you could also ask if they can make a special order of Genius bread for you to collect as some of our other customers have found stores willing to do this for them when they have had difficulty in obtaining it.
I have deliberately not looked at that website CMOT......although I might look into bulk ordering as I'm fed up going for my breakfast flakes to either tesco or sainsbury's and them being out of stock.