Chosen Solution

when i bought the new phone it was charging perfect but after two months the charging gets slow and i visited the service center and purchased a new charger. Again same thing happened. what to do?

Seems like Samsung is trying to push some bad chargers instead of discarding them. Have you tested its behaviour when charging from USB? If you have a non-Samsung charger, but with the EXCACT SAME specs, it might save you some money and time from going to buy a new one every 2-3 months.