Iphone 15 Plus - Liquid Detected

Hi, I took my new iphone 15 plus (5 months old) to an apple authorized service provider to check it, because i couldn't charge it, after the notification i was getting that liquid was detected, even though that the phone never got wet.

Does the authorized service provider had the wright to open the phone without my consent??? I have pictures proving that they opened it, along with the report.

The result of the check, was that they couldn't fix it, and that they were offering me to buy a new one with a discount of 30%!!!

Please for your comments about opening the phone.

Thank you