Two months after the battery was changed, it became bloated and could not be used.
He feedback the issue to the shop owner.
The owner replaced another new battery for him.
Two weeks later, he noticed the percentage on the battery indicator stopped increasing at a certain percentage while charging. But when he rebooted the phone, the battery would shoot up to 90%. And the phone would shutdown by itself and dropped to zero percent even when there's still 40% or 60% battery left. The battery also started to bloat.
He informed the owner again.
The owner replied, "Mine is a small business. There is a limit to what I can do for you."
The man is contemplating whether to send to the official repair shop to check if any of the internal part of the phone is damaged. This will probably costs in a few hundred dollars.
Might as well buy a new phone.