To delete your account do the following:
1. Click on 'Profile'.
2. Click on 'Basic Details'.
3. Under 'PROFILE VISIBILITY' and 'Who may view your profile?' choose: 'Delete profile'.
4. Click on 'Save Basic Details and Settings'
Keep in mind that should you wish to join again at a later date that you will need to answer all the survey questions again. Therefore, you may wish to consider only hiding your account, just in case you decide you'd like to use it again at a later date. You can hide your account by clicking on 'Profile'. Then click on 'Basic Details'. Under PROFILE VISIBILITY choose 'Set my profile to invisible (hide profile and make it in-active)'