It depends on your region to utilize the purge feature. You mentioned your account is 70 days old. If your QBO region is allowed to purge it, the system will remove all data and you can start from scratch. It is why we recommend to export all of your data out to CSV/XLS to let you import some data to speed up the rework process. When the system is not allowed to purge it, you don't have any option but opening a new QBO account and import some data if required. Don't forget to cancel your old account.