[SOLVED] How do I keep developer products from repeating on entry?

Edit: I forgot to tell the server that the purchase had been processed. I created a developer product that allows you to purchase more credits, but then, if you leave and rejoin, you get the same amount of credits again. Does anyone know how to fix this?

Here is the script:

local mps=game:GetService("MarketplaceService")
function getPlayerFromID(id)
    local plrs=game.Players:GetPlayers()
    for i=1,#plrs do
        if plrs[i].userId==id then
            return plrs[i]
        end
    end
end
mps.ProcessReceipt=function(info)
    if info.ProductId==22821479 then
        local plr=getPlayerFromID(info.PlayerId)
        plr.leaderstats.Cash.Value=plr.leaderstats.Cash.Value+1000
    elseif info.ProductId==22821510 then
        local plr=getPlayerFromID(info.PlayerId)
        plr.leaderstats.Cash.Value=plr.leaderstats.Cash.Value+2500
    elseif info.ProductId==22821535 then
        local plr=getPlayerFromID(info.PlayerId)
        plr.leaderstats.Cash.Value=plr.leaderstats.Cash.Value+5000
    elseif info.ProductId==22821547 then
        local plr=getPlayerFromID(info.PlayerId)
        plr.leaderstats.Cash.Value=plr.leaderstats.Cash.Value+10000
    end
end

If you can help me, that'd be great!