MarketplaceService bugg (double ProductId)?

Hi devs. I have a little problem with my Marketplace. If per example i buy 200 xp, i'll get receive them normally, but as soon as i try to buy another thing all previous item execute again, why and how?

I dont know if you guys understand what I mean

If I buy xp/money

First purchase output:

439092562

Now if I buy money/xp

Secondly purchase output:

439092562 (x2)

439094412

I recieve xp and money id, why and how?

LocalScript Explorer

--< Services
local PlayerService = game:GetService('Players')
local MarketplaceService = game:GetService('MarketplaceService')

--< Events
for _, SurfaceGui in pairs(script.Parent:GetChildren()) do
    if SurfaceGui:IsA('SurfaceGui') then
        for _, ImageLabel in pairs(SurfaceGui.Shop:GetChildren()) do
            ImageLabel.Button.MouseButton1Click:Connect(function()
                MarketplaceService:PromptProductPurchase(PlayerService.LocalPlayer, ImageLabel.Name)
            end)
        end
    end
end

Script

local PlayerService = game:GetService('Players')

MarketplaceService.ProcessReceipt = function(ReveipInfo)
    local Player = PlayerService:GetPlayerByUserId(ReveipInfo.PlayerId)
    local ProductId = ReveipInfo.ProductId
    if ProductId == 439094412 then -- +325 money
        DataManager:ChangeStat(Player, 350, 'Money', true)
        print(ReveipInfo.ProductId)
    elseif ProductId == 439103355 then -- +550 money
        DataManager:ChangeStat(Player, 550, 'Money', true)
        print(ReveipInfo.ProductId)
    elseif ProductId == 439103573 then -- +875 money
        DataManager:ChangeStat(Player, 875, 'Money', true)
        print(ReveipInfo.ProductId)
    elseif ProductId == 439104104 then -- +1,200 money
        DataManager:ChangeStat(Player, 1200, 'Money', true)
        print(ReveipInfo.ProductId)
    elseif ProductId == 439092562 then -- +200 exp
        DataManager:ChangeStat(Player, 200, 'Experience', true)
        print(ReveipInfo.ProductId)
    elseif ProductId == 439092841 then -- +400 exp
        DataManager:ChangeStat(Player, 400, 'Experience', true)
        print(ReveipInfo.ProductId)
    elseif ProductId == 439093127 then -- +800 exp
        DataManager:ChangeStat(Player, 800, 'Experience', true)
        print(ReveipInfo.ProductId)
    elseif ProductId == 439094114 then -- +1,600 exp
        DataManager:ChangeStat(Player, 1600, 'Experience', true)
        print(ReveipInfo.ProductId)
    end
end