Oppo Reno 14 F Severe Lag Issue While Gaming

I bought my Oppo Reno 14 F phone on 25 March 2026, and from the first day I have been experiencing a serious performance problem. The device lags excessively, especially while playing the e-Football game, and this situation has continued in the same way until today without any improvement. Because of this persistent problem, I contacted both the seller and Oppo service. They recommended a software update and told me to delete and reinstall the game I was playing. I applied all these recommendations one by one, updated the software and deleted and reinstalled the e-Football game, but the lag problem did not improve at all and continues exactly the same. I cannot use the phone as advertised or as I expected at the time of purchase, and I am seriously disappointed. I request a full refund for the Oppo Reno 14 F and an official apology for the inconvenience and loss of time caused by this unresolved performance problem.