Hey dhaval1803. Sorry to hear of your difficulties with the remote. Happy to help out where we can. Originally, what issues were you experiencing with the remote? Have you tried replacing the batteries a second time, and testing all of the button inputs on the remote?
If issues persist, let's try resetting the remote. On the remote, press and hold the volume down and left navigation buttons for five seconds. The LEDs on the top of the remote should flash. If they do flash, there is power to the remote and you can try pairing it back with your Soundbar 700. Our guide HERE talks through the next steps to take to pair the devices together once again.
Should the remote not react when pressing the volume down and left button, and all lights remain off regardless of pressing any buttons on the remote, there may be a hardware fault. Should this be the case, please reach out to your local Bose support for service assistance with replacing the remote. Click HERE, select your location, and use the "Contact us" section at the bottom of the page. Let us know how you get on.