From what I have heard on twitter, Razorpay is very unreliable in case of international credit cards. Stripe is the default option, but now it's invite only. Paddle seems to be the go-to option right now. It acts as a MoR, which can be good or bad depending on your requirements.
Why don't you get the battery replaced? A friend of mine replaced the battery in his 3-year-old flagship, and he says that not only is the battery life as good as new, but the performance has also improved.
"Campaign Period: The Campaign will run from April 29, 2024 to October 28, 2024 (or till such date the stocks last (whichever is earlier)), with both start and end dates included in the CampaignPeriod."
This is from t&c pdf