Mario Kart code missing from Nintendo Switch box bought in Smyths

I've never done a chargeback before. The thing is that I did receive the Switch which was the bulk of the cost, just not the game. It was at the end of November also, would either of those things prevent a chargeback?
As far as I know you have 6 months from date of transaction to initiate a chargeback claim

On the AIB website they say reasons for charge back are...
  • Non-delivery, where the cardholder disputes the sale for reasons such as failure to receive goods or services
Not sure if you get the whole amount back or just the value of the game but I'm sure if you have to contact the bank for this that somebody there will advise you of what you be entitled to claim for and what you need to do to start the process
 
Have you tried sending a strongly worded letter of complaint to Smyths since Nintendo bowed out of the problem? Google their CEO and write to them.
Mr Smyth - Pádraig and Tony to be precise. Mervue Business Park, Galway
In reality it's the manager of the local store that should deal with it
 
UPDATE
I went to Smyths the week before last and explained the situation to them in person. They were very empathetic and said to leave it with them and Head Office would deal with it. 6 days later I got a call from Smyths with a code for the Mario Kart game which is now successfully installed on our Nintendo Switch. Thank you to all for your replies and advice.