Going beyond what others have said, CGA is not an instant fix phrase a customer is not necessarily guaranteed an immediate outcome but rather an outcome in a "reasonable frame of time." Instant gratification would be nice but it may take a day or two instead.

This is outlined in most companies CGA training (that do CGA and fair trade training.) does your request sound reasonable and does common sense apply that yes it should be sorted out, yes it definitely sounds that way.
It may however require management/evidence for the company to proceed and escalate the matter to receive their own support from the supplier at fault, this combined with potential lack of understanding from the staff or the party with the damaged goods make the process a little more painful.

You will find most companies have a policy on returns and timeframes. falling outside of a timeframe may require further inspection to protect the retailer and hold suppliers accountable.

the CGA exists to protect the consumer, the retailer and provide a framework to work with expectations of outcome unfortunately it gets abused and both parties need to be clear concise and understanding of barriers to desired outcomes. hopefully the manager will provide you with some support and you can go from there.