CEX Issue - Stole My Airpods And Swapped For Fakes **Resolved and Refunded by CEX**

I traded in my AirPods online at CEX. However, today I received an email saying that they are being sent back to me as they are 'suspected counterfeit'. I am almost certain that they aren't as they were purchased from Very and the legitimacy has been confirmed by Apple. What do I do here? Can I go and trade them in at a CEX store instead?

UPDATE: Received Airpods back and they are fake and not the ones I sent to them. Therefore, someone at CEX has stolen my genuine Airpods and currently I've lost £75.

UPDATE 2: £75 payment received