Samsung Galaxy Battery Drains Fast When Using Internet

"Yesterday, I spoke with Ms. E*** from the Solution Center. I would like to thank her very much for showing the necessary attention. She explained that since the device was formatted during the software update, the battery usage data was not visible, and that I should take the device from the service, use it for a few days, and then bring it back to the service. I accepted this. A short while ago, I visited the MTA Elektronik Incirli Service to pick up my device. After waiting in line for a short time, they called my name. When I went to receive my device, I was shocked to see that, even though they knew I absolutely did not want any repairs, they had removed the screen protector worth 600 TL from my phone. My blood pressure shot up, and I became suspicious. After examining the phone a bit more, I noticed a dent the size of a fingernail on the lower right corner. Your authorized Samsung services are completely disgraceful—I am stating this clearly and openly. I had to take the device because I was in a hurry, but this is unacceptable, Dear Samsung Officials. On top of that, you say you tested the device and found no issues. When I received it, the battery was at 38%. I installed 2 applications and made 1 call, and now it is at 30%. Is this the device you say has no problems? Shame on you, really shame on you."