The subscription model is based on, to put it mildly, highly dubious 'business practice' where you can't stop subscription, the only option provided is to pause is for up to three months, then they continue to charge your credit card. It seems that the only way to stop it is to send a request to help desk and wait. Advice - make sure you use prepaid credit card with limited amount of credit when dealing with Packt to avoid abuse.
Claim your business profile now and gain access to all features and respond to customer reviews.