It is tough as there seems to be no cancellation process. However after much time spent online and on the phone I got through by calling Virginmobile at 1-888-322-1122 After answering a couple of questions I realised that this automated service didn't have a cancellation option either so I stopped answering the questions eventually being asked "if you want to speak to an advisor press 2 or I will hang up" so I pressed 2 and I then got through to a real person who transferred me to cancellations, it is a long way round but I got there.
If you mean Assurance Wireless, you will need to contact a customer care representative and let them know that you would like to cancel the service. Assurance Wireless reserves the right to modify or cancel this service or your account. For more information, visit http://www.assurancewireless.com/Public/TermsOfServiceRider.aspx.