Why does my Random Gift shop script sometimes charge multiple times?

Hello!

I have a random gift shop script. When the Player presses the button, a pop-up purchase menu appears with the Buy button. Once the Buy button is selected, script checks if the player has enough money, if so, it will then begin the random number process, "if between 1 and 10 then" it gives the item. If a player already has the item, it moves on to the next item, this way, no item is awarded twice.

Only problem here is occasionally, it will award, and charge, more than once, per button press. This happens seemingly randomly. I'd rather this not happen. Here is an abbreviated version of the script, which is a Local Script inside a GUI:

--//Get Services
local   ReplicatedStorage = game:GetService("ReplicatedStorage")
local   Players = game:GetService("Players")
local   Player = Players.localPlayer
--//EventFolder
local   Events = ReplicatedStorage:WaitForChild("Events")
--//Events
local   UpgradesCoinsPurchase = Events:WaitForChild("UpgradesCoinsPurchase") -- This is the Remote Event which handles the purchases.

local   currencyCOINS = Player.leaderstats.Coins
local   CoinsLeaderstats = Player.leaderstats.Coins

item1_event = nil

math.randomseed(tick())
CRATESButton.MouseButton1Click:Connect(function()

if item1_event then item1_event:disconnect() end
item1_event = Item1.MouseButton1Click:Connect(function()

local    Item1Coinsbutton  =  script.Parent.Frame.CRATESFrame.Item1Frame.BuyCoins
script.Parent.Frame.CRATESFrame.Item1Frame.CoinsPrice.Text  = 100
Item1Coinsbutton.MouseButton1Click:Connect(function()
local    amount  = 100
local    descText  =  script.Parent.Frame.CRATESFrame.Item1Frame.DescriptionFrame.ItemDescription
local    random  =  math.random(1,200)
local   debounce = false

if debounce == false and  Player.leaderstats.Coins.Value >=  amount then
    debounce = true
if  random >=  1 and random <=  10 then 
local   Item01 =  Player.Inventory.HasItem01Blue
if Item01.Value  ==  false then
UpgradesCoinsPurchase:FireServer(Item01, amount)
 descText.Text  =  'You received  Item01Blue! Check your Blue Inventory!'
elseif Item01.Value  ==  true then
 descText.Text  =  'You received  Item01Blue! You already own this item. Try again!'
end
wait(3)

elseif  random >=  11 and random <=  20 then 
local   Item01 =  Player.Inventory.HasItem01Green
if Item01.Value  ==  false then
UpgradesCoinsPurchase:FireServer(Item01, amount)
 descText.Text  =  'You received  Item01Green! Check your Blue Inventory!'
elseif Item01.Value  ==  true then
 descText.Text  =  'You received  Item01Green! You already own this item. Try again!'
end
wait(3)

--etc. etc.

This is the script for the Remote Event which handles purchases.

--//Get Services
local ReplicatedStorage = game:GetService("ReplicatedStorage")
--//Event
local Events = ReplicatedStorage:WaitForChild("Events")
local UpgradesCoinsPurchase = Events:WaitForChild("UpgradesCoinsPurchase")

UpgradesCoinsPurchase.OnServerEvent:Connect(function(Player, Value, Amount)
Player.leaderstats.Coins.Value = Player.leaderstats.Coins.Value - Amount --Subtract money from the player
        print(Value)
        Value.Value = true
end)

From the Print of the Value being purchased in the Remote Event script, I can verify multiple items are being purchased/charged. But its random how often it happens. Most of the time it acts as intended and only awards/charges for a single purchase, but I can't have the random chance of it charging multiple times and sending a Player's currency into the negative numbers.

Anyone have any suggestions for how to eliminate the random purchase factor from my random gift script, or if there's a better way to script my random gift giver that also prevents duplicate gifts? ...The irony of a random problem with a random script is not lost on me. :D