Cannot update self in lua class?

Question

function _GetWhitelist(name)
    if not _whitelists[name] then
        print('Unable to get whitelist ('..name..') - does not exist')
        return false
    end

    local Whitelist = {}
    Whitelist.__index = Whitelist

    function Whitelist.new(wl)
        local self = setmetatable({}, Whitelist)
        self.name = wl.name or 'unknown'
        self.roles = wl.roles or {}
        self.players = wl.players or {}
        self.duty = {}

        function self:getName()
            return self.name
        end

        function self:changeName(something)
            self.name = something or 'unknown'
            print(self.name)
        end

        return self
    end

    return Whitelist.new(_whitelists[name])
end

    WL = _GetWhitelist('police')
    print(WL) -- print the object reference
    local wl_name = WL:getName()
    print('Created whitelist: '..wl_name)
    WL:changeName('testing')
    print('Changed whitelist name to: '..WL:getName())

The print inside the changeName() function prints the correct value, but the following WL:getName() always returns the orignal value, is there a way I can update the self values? Any help would be appreciated, first time using lua classes like this :)

Tried to update the values inside self, but they didn't update when I called the getName() function again.