African Directly Services Scammers

On the 27/02/19 received a call from Thandeka , of which she has been calling for weeks to get hold of me , after our chat she sent through a registration form , we filled it in and sent it through for their advertising purposes but then we realized that we do not need their services and sent through an email to cancel our Registration for of which it stated that for their services we need to pay an amount of R1459.00 when they will advertise our Company... As the email was sent to them to cancel the services we keep on receiving invoices for services not used by us, nor agreed on an Layout of the Ad . Now all of a sudden we owe them R22 694.10??? within a period of 3 months cancelling the service.