Marshall Emberton Bluetooth’s Speaker Charging Issue

I have a Marshall Emberton speaker that I bought 4 years back. Now it isn’t getting charged and the customer care says that there is no repair support for this product. I’ve tried resetting the speaker, using different charging cables and chargers, etc. However nothing seems to work. When I connect it to the charger, the charging light blinks. However, no matter how long I leave it for charging, on disconnecting the charger, it only shows 2 lines of charge. And it gets discharged in no time. I think the battery needs replacement. Please confirm if anyone has had an identical or similar issue and suggest, what should be done to resolve this issue.