Why is developer product purchase script not working?

Okay guys I will try to be quick and organized.

I have one LocalScript in a GUI that consists of this

wait(0.1)
local player = game.Players.LocalPlayer
local currency = player:WaitForChild('leaderstats').Coins
local devid = IDHERE --Give # of coins
Open = false


itembutton.MouseButton1Click:connect(function()
    game:GetService('MarketplaceService'):PromptProductPurchase(game.Players.LocalPlayer, devid)
end)

and then I have another script in ServerScriptService as such

MarketplaceService = game:GetService("MarketplaceService")
local devid = IDHERE


MarketplaceService.ProcessReceipt = function(receiptInfo)
    for i, v in pairs(game.Players:GetChildren()) do    
    if v.userId == receiptInfo.PlayerId then
        if receiptInfo.ProductId == devid then
        v.leaderstats.Coins.Value = v.leaderstats.Coins.Value + 100
        local DataStore = game:GetService("DataStoreService")
        local ds1 = DataStore:GetDataStore("coins")
        ds1:SetAsync(v.UserId, v.leaderstats.Coins.Value)   
        wait()
            end
        end     
    end
    return Enum.ProductPurchaseDecision.PurchaseGranted
end

The problem is that I am not getting the plus 100 coins that I should be getting upon buying the devproduct id. The LocalScript works fine, it shows the devproduct and I can purchase it, but then after that I do not get my 100 coins. Why exactly is this? Could you give me any ideas? I have tried resetting the character, still nothing.