I received a call today at 17:20 from the number 2018.06.0501372 402587, which seems to be linked to the Esher region in Surrey. Strangely enough, as soon as I picked up, the call disconnected immediately. When I attempted to return the call, I was met with a BT message stating, "The number you have dialled is not recognised. Please verify and try again." Quite odd, isn't it?