My Suggestion Request in the AppMySite Community as a Feature Request:
Add more security layer for account deletion by mistake, and I suggest to add more deletion security layer for example by email confirmation with security code to be entered or by optional Google authentication app., or by sending email to support team.
Thanks
I think they already have several layers of security. For instance we get a confirmation prompt, and we are also asked to remove all apps before deleting the account. Hope this helps! 
To add to what @Riya said you’ll also have to cancel any subscriptions you have with them before being able to delete your apps and then subsequently your account.