Samsung — Software complications

I am Ashish kumar parida, currently having a handset of samsung galaxy F54 5G.
Recently someone breached my phone screen lock pin and some how reset that pin and then turn off the remote unlock option and then in find my mobile lock it from the same phone. When I firstly try to unlock with my pin it denied and after certain trials I end up locking the device permanently. In the screen it shows to go for service center but when I arrived they are not even able to reset it.
Now I got call that that can not be retrieved. It is just 4 month since I brought it.
After this type of service I loss my faith samsung phones.
Please take it seriously and resolve my problem.