Bad and unfair customer treatment by Discovery

I got an Apple Watch via Discovery Vitality in Feb 2020. Discovery Vitality sets customers monthly fitness goals which customers are supposed to meet else they pay a certain penalty fee. Sometimes in June 2021 I got an email from Discovery Vitality stating that I owe them as I did meet the monthly goals for about 3 months of which it was incorrect. I sent them all screen dumps to update manually on their system and they told me they have done that. In Nov 2021 I received some calls from lawyers acting on behalf of Discovery demanding me to pay about R3000. I refused paying because I know and have proof that I met on monthly fitness goals. When i contact Discovery Vitality, they send me from pillar to post, they say I should deal with Discovery Bank of which I tried without success. Recently when I contacted Discovery Vitality they told me that my Apple Watch is black listed.