Airpods pro not pairing, after pods replacement at genius bar

I got airpods pro online marketplace. It had some issues like case over heating only on wireless charger, transparencey not working, and spatial audio was not up to the mark. I took them apple store, they replaced the pods, but not the case. Asked me to charge overnight and pair them in the morning. Now they do not connect to my phone. In my second trip to Apple store, they asked me send the whole package - airpods pro case and pods to the authorized service center. They returned saying unauthorized modification done to the case, hence they cannot cover in the warranty. In my 3rd trip to Apple store today they are calling it fake and refrain from replacing the case. They only replaced the pods on day 1, suggested not to replace the case, and now calling it fake. Before buying I checked for authenticity of the product by looking up the serial number, it showed me a warranty till 12/31/2022. Now everyone is just backing out from the committments. Since this is a gift to my wife, I am even willing to pay for the replacement case, just to make them work. The apple store/genius bar folks are so non-cooperative, and not willing to help. Their employee with whom I worked has already left the job, and rest of them are not helping. I am looking for a replacement case, and want to know the pods that the employee replaced are genuine or not.

Seeking help and answers from the community