Radio gui chat error

Whats happening:
[Class D] [vf9r] asdsad
[Class D] [vf9r] asdsad
[Class D] [vf9r] asdsad
[Class D] [vf9r] asdsad
[Class D] [vf9r] asdsad
[Class D] [vf9r] asdsad

What I want to happen
[Class D] [vf9r] asdsad
[Administrator] [admin11] asdsasd

The script I am using to replicate the chat to the radio:

local enabled=script.Parent.IsRadioEnabled
local plr=game.Players.LocalPlayer
local m = script.Parent.Main
local chatboxes={m.cb1,m.cb2,m.cb3,m.cb4,m.cb5,m.cb6,m.cb7,m.cb8,m.cb9,m.cb10,m.cb11,m.cb12}

plr.Chatted:Connect(function(msg)
	if (enabled.Value==true) then
		print(msg)
		for i,v in pairs(chatboxes) do
			if (v.Used.Value==false) then
				v.Text = "["..plr:GetRoleInGroup(8204505).."] " .. "["..plr.Name.."] "..  msg 
			end
		end
	end
end)

How do I make it so it goes only one chatbox at a time and when it’s full it just starts deleting the top messages?