It is the THREE (Mobile Network) sales department. When you sign up with them they send you occasional calls every month to try and persuade you to upgrade to a better package (and restart your contract period), And do it more the closer you get to the end of your current contract. You can always tell it is Three because they always call from a 033333xxxx number.
Keeps calling 2/3 times a day every day in the morning and lunchtime. I answered and no one is there so number is now blocked. There are different variations of this number used all starting with 0333338. Don‚Äôt bother answering them.
0333 numbers are examples of a non-geographic phone numbers. These are numbers that are not linked to any locality within the UK. They were introduced in 2007 as an alternative to the traditional landlines that were usually assigned geographically through the use of a system of location-specific area codes. All 0333 numbers are landline numbers. However, unlike the ‘01’ or ‘02’ landline numbers, you cannot identify the area 0333 numbers are associated with.