[SDPhantom]

In that case, just remove that entire SPELL_CAST_SUCCESS block. That event fires when the spell finishes casting, no matter if it took effect on the target or not. I would also suggest havint the spell check before the other conditionals since no matter what event type is triggered, you'd want to exit if it's a spell you want to exclude.

This is what I have in mind:

--  Spell List
local spellData = {
 
--  Class Spells
 
    [2139] = { -- Counterspell
        cooldown = 24,
--      texture = "Interface\\Icons\\spell_frost_iceshock",
    },
    [1766] = { -- Kick
        cooldown = 15,
    },
    [47528] = { -- Mind Freeze
        cooldown = 15,
    },
    [6522] = { -- Pummel
        cooldown = 15,
    },
    [96231] = { -- Rebuke
        cooldown = 15,
    },
    [80964] = { -- Skull Bash (Bear Form)
        cooldown = 15,
    },
    [80965] = { -- Skull Bash (Cat Form)
        cooldown = 15,
    },
    [57994] = { -- Wind Shear
        cooldown = 12,
    },
    [34490] = { -- Silencing Shot
        cooldown = 20,
    },
    [15487] = { -- Silence (Priest)
        cooldown = 45,
    },
    [47476] = { -- Strangulate
        cooldown = 120,
    },
--  [108194] = { -- Asphyxiate
--      cooldown = 20,
--  },
    [116705] = { -- Spear Hand Strike
        cooldown = 15,
    },
 
--  Racials
 
    [28730] = { -- Arcane Torrent (Mana)
        cooldown = 120,
    },
    [50613] = { -- Arcane Torrent (Runic Power)
        cooldown = 120,
    },
    [80483] = { -- Arcane Torrent (Focus)
        cooldown = 120,
    },
    [129597] = { -- Arcane Torrent (Chi)
        cooldown = 120,
    },
    [25046] = { -- Arcane Torrent (Energy)
        cooldown = 120,
    },
    [69179] = { -- Arcane Torrent (Rage)
        cooldown = 120,
    },
}
 
local eventFrame = CreateFrame("Frame")
eventFrame:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED")
eventFrame:SetScript("OnEvent", function(self,event, _, combatEvent, _, sourceGUID, _, _, _, _, destName, _, _, spellID, spellName, _, extraSpellID)
 
--  Only allow player and specific spells we handle
    local spell=spellData[spellID]
    if sourceGUID ~= UnitGUID("Player") or not spell then
        return
    end
 
--  Success/Fail Messages
    if combatEvent == "SPELL_INTERRUPT" then
        SendChatMessage(format("%s > %s's %s",GetSpellLink(spellID),destName,GetSpellLink(extraSpellID)),"Say")
    elseif combatEvent == "SPELL_CAST_MISSED" then
        SendChatMessage(format("%s has failed to interrupt !!!  %.0fs CD",GetSpellLink(spellID),spell.cooldown),"Say")
    elseif combatEvent == "SPELL_CAST_FAILED" then
--      Remaining Time Message
        local start, duration, enabled = GetSpellCooldown(spellID)
        if enabled==1 and duration>0 then
            SendChatMessage(format("%s's CD has %0.1fs left", GetSpellLink(spellID), (start + duration) - GetTime()), "Say")
        end
    end
end)

Note, I shortened the code a bit, renamed the variables receiving GetSpellCooldown()'s returns to conform with Blizzard's Add-On Development Policy regarding obfuscation, and cleaned up the event handler's parameters. The unused handler parameters have been renamed to the variable _ , which even though it's considered in Lua as just another variable, it's commonly used for this and is easier to distinguish as a value that isn't important.

EDIT: Removed the condition for SPELL_AURA_APPLIED since in some cases, it may cause spaming when using an AoE ability like Arcane Torrent. This will also fix some cases of success messages sending twice.

Note, SPELL_CAST_FAILED should also be considered for possible spam as some players may "mash" the ability when trying to cast it.