Larry!

Is it a Tesco plant? I saw a lot in Tesco! I think it is albiflora (variant or a hybrid plant I don't know)

I got it from Wilkinson's , 3 for £1.30 or 80p each

M.zeilmanniana v albiflora has yellow bud, later when it opened you can see these bright white flowers.

I think it was for a long time on a shady side of the shop. zeilmannianas are strong plants. They are able to survive a lot of mistakes of keeping.