What is your approx location? Nearest town, or first part of postcode?
If it goes in the post, the earliest it could possibly arrive is Wednesday, due to the bank holidays.
There may be a member near you, if you give us a clue about where you are. But remember this is a public forum.
@nuribey Due to the urgency, pop down to your local Tesco, sainsbury, Iceland, poundland, Asda and choose any giffgaff sim.
If however you reported your sim lost or stolen, then you will need to wait for your replacement sim to arrive at your home address.