It wasn’t a service deficiency, the contract promised you’d get included luggage and you didn’t receive it. It would be like me buying an iPhone 15 and Apple sending me an iPhone SE. it was not what a bargained for.
Alternatively you can chargeback Malaysian Airlines for being double charged for a service you already paid for.
You may want to raise this to the financial services ombudsman or alternatively your state consumer affairs department.
A lot of it comes down to chasing down the right person. It will take some time. Whether it is worth it is a value judgement only you can make.
And Malaysia airlines for that matter. Poor accrual on QFF, poor service and communication plus having to connect in KUL, an airport that makes even the old LaGuardia look good
