AirPods 2 Warranty tampering

Hi, incredible situation.

I bought AirPods 2, November 2022.

Open for a few days, the cone feels good, but the microphones, the voice feels muffled and distant.

I call Apple, the headphones are picked up by the courier. After 7/8 days I receive emails that the headphones have been tampered with.

I have not tampered with anything, which is absurd beyond belief.

They canceled my warranty, I called them, and they can't tell me the real reason, the technicians said they've been tampered with.

They accept no reasons

I'm Italian, I've been a loyal Apple customer for more than 20 years, for the first time I needed assistance, this was the treatment.

I have headphones to throw !!!!!!! Because if the microphones don't work the colap is mine !!!!!!!!!!!! I opened them or tampered with them, they treated me like a scammer, I have no words.

They told me that if I send again under warranty, they will charge me 100 euros, UNBELIEVABLE

I'm infuriated, I'm a customer, and I'm being treated like a scammer!!!!

What can I do ? Who should I contact

Thank you