Debt after canceled

So I was trying out this app but was trying to get it to work with my fitness device but doesn't work I then canceled my subscription on the 25 March 2021 that was 3 day's before my subscription date to go live for my first payment of R599 then on the 28 March 2021 at 19:00 I got sms from my bank for deductions of the R599 and no where to call or email.