How to make these developer products more reliable?

Ok so this is the script I made for purchasing currency, and apparently people sometimes aren't getting their currency... Anyway to fix this? People are getting really mad at me

local MarketplaceService = game:GetService("MarketplaceService")
 
MarketplaceService.ProcessReceipt = function(receiptInfo)
	--game.Workspace.DisplayScreen.SurfaceGui.TextBox.Text = receiptInfo.PlayerId .. " just bought " .. receiptInfo.ProductId
	if receiptInfo.ProductId == 25740543 then--1000
	local players = game.Players:GetChildren()
	for i=1,#players do
		if players[i].userId == receiptInfo.PlayerId  then
			players[i].leaderstats["Tokens"].Value = players[i].leaderstats["Tokens"].Value + 1000
			local gui = game.ServerStorage.assets.EXTRAINFO:Clone()
			gui.TextLabel.Text = (players[i].Name.." just bought $1,000 Tokens")
			gui.Parent = game.Workspace.game.Gui			
			break
		end
	end
	elseif receiptInfo.ProductId == 25740553 then--7500 
	local players = game.Players:GetChildren()
	for i=1,#players do
		if players[i].userId == receiptInfo.PlayerId  then
			players[i].leaderstats["Tokens"].Value = players[i].leaderstats["Tokens"].Value + 7500
			local gui = game.ServerStorage.assets.EXTRAINFO:Clone()
			gui.TextLabel.Text = (players[i].Name.." just bought $7,500 Tokens")
			gui.Parent = game.Workspace.game.Gui			
			break
		end
	end	
		
	elseif receiptInfo.ProductId == 25740591 then--20,000 
	local players = game.Players:GetChildren()
	for i=1,#players do
		if players[i].userId == receiptInfo.PlayerId  then
			players[i].leaderstats["Tokens"].Value = players[i].leaderstats["Tokens"].Value + 20000
			local gui = game.ServerStorage.assets.EXTRAINFO:Clone()
			gui.TextLabel.Text = (players[i].Name.." just bought $20,000 Tokens")
			gui.Parent = game.Workspace.game.Gui			
			break
		end
	end	
	elseif receiptInfo.ProductId == 25740608 then -- 1,000,000
	local players = game.Players:GetChildren()
	for i=1,#players do
		if players[i].userId == receiptInfo.PlayerId  then
			players[i].leaderstats["Tokens"].Value = players[i].leaderstats["Tokens"].Value + 1000000
			local gui = game.ServerStorage.assets.EXTRAINFO:Clone()
			gui.TextLabel.Text = (players[i].Name.." just bought $1,000,000 Tokens")
			gui.Parent = game.Workspace.game.Gui			
			break
		end
	end		

		
		
		
	end
	return Enum.ProductPurchaseDecision.PurchaseGranted		
end