User converted via automatic rule On Customer Creation

user is automatically converted in customer via automatic rule On Customer Creation and too many communication gets linked with it, but user is not at all customer if i try to delete the customer it popups for cannot delete as it is linked with communication but if i check for communications it shows no link in it can anyone help on

1)how to delete the customer
2)how to remove link between the customer and communication in order to remove the customer
3)there are links in communication and the email ques also how to unlink the same