Garbage Service and No Warranty for Oppo Reno 5 Lite

I own an Oppo Reno 5 Lite phone, and I took it to the KVK service for battery and earpiece issues. To my dismay, they refused to honor the warranty, claiming that the manufacturer didn't accept it. What a waste of money! Oppo is nothing but regret. They even said the phone's casing was crooked. They took my 2400 lira and returned the phone still crooked. When I pointed it out, they blamed it on a crooked display. Then they had the audacity to demand 7000 lira for repairs. I've written to CİMER (Presidency of the Republic of Turkey Communication Center) about this terrible experience. I will never let another Oppo product with a warranty set foot in my house. Shame on them!