Skip Level Product Won't Work?

I spent an hour making a skip level button for my friend's game to figure out it doesn't work. When I go from 0 to 1 it works, then when I buy it to go to the 2nd level I go to the 3rd level. Enough talking, here's the code.

local MS = game:GetService("MarketplaceService")
function MS.ProcessReceipt(receipt)
	local Player = tostring(receipt.PlayerId)
	local character = game.Players:GetPlayerByUserId(receipt.PlayerId).Character
	local CheckpointData = game.ServerStorage:FindFirstChild("CheckpointData")
	local PlayerData = CheckpointData:FindFirstChild(Player)
	if PlayerData then
		local A = tostring(PlayerData.Value)
		local LevelWord = "Level"
		local Number = string.sub(A,#LevelWord+1,#A)
		local NumberA = tonumber(Number)
		local NumberB = NumberA+1
		local LevelPart = game.Workspace:FindFirstChild("Level"..NumberB)
		PlayerData.Value = LevelPart
		character:MoveTo(LevelPart.Position + Vector3.new(math.random(-4, 4), 4, math.random(-4, 4)))
	else
		local New = Instance.new("ObjectValue",CheckpointData)
		New.Name = tostring(receipt.PlayerId)
		New.Value = game.Workspace.Level1
		character:MoveTo(game.Workspace.Level1.Position + Vector3.new(math.random(-4, 4), 4, math.random(-4, 4)))
	end
end

Edit: In case you need it, here is the checkpoint script.

local Players = game:GetService("Players")
local ServerStorage = game:GetService("ServerStorage")

local checkpoint = script.Parent

function onTouched(hit)
	if hit and hit.Parent and hit.Parent:FindFirstChildOfClass("Humanoid") then
		local player = Players:GetPlayerFromCharacter(hit.Parent)
		local checkpointData = ServerStorage:FindFirstChild("CheckpointData")
		if not checkpointData then
			checkpointData = Instance.new("Folder")
			checkpointData.Name = "CheckpointData"
			checkpointData.Parent = ServerStorage
		end
		
		local userIdString = tostring(player.UserId)
		local checkpointValue = checkpointData:FindFirstChild(userIdString)
		if not checkpointValue then
			checkpointValue = Instance.new("ObjectValue")
			checkpointValue.Name = userIdString
			checkpointValue.Parent = checkpointData
			
			player.CharacterAdded:connect(function(character)
				wait()
				local storedCheckpoint = ServerStorage.CheckpointData[userIdString].Value
				character:MoveTo(storedCheckpoint.Position + Vector3.new(math.random(-4, 4), 4, math.random(-4, 4)))
			end)
		end
		
		checkpointValue.Value = checkpoint
	end
end

checkpoint.Touched:Connect(onTouched)