Volunteer organization. Unknown user, password, contact person, nature of service.

We are a volunteer organization and we received an overdue notice from Telus.  We do not know what the service is for, do not have an invoice or statement, do not have a contact person from the organization, do not know user name or password or pin.  Telus will not speak to anyone here in the volunteer organization because of lack of information, but are threatening us for non-payment.  Calling them at their number is useless because they do not seem to be able to help.  Don't know what to do next and it seems a collection agent is trying to collect now.  Very disappointed with Telus as nobody we call will help because of our lack of information. Will never recommend them again.