@MeenakshiG: I agree that, based on the nature of the issues you're experiencing, an engineer's inspection would be beneficial in this instance. Before proceeding I recommend backing up the device and performing a factory data reset, as this will return the phone to its default factory settings, and potentially resolve any software or hardware issues. For further guidance, please take a look at the link below.
If the problem persists, then please head to samsung.com > Scroll to the bottom of the screen > Contact us, and get in touch via your preferred contact method, and an advisor will be on hand to assist you further.
