Unauthorized Debit order

I moved to UK and had to pay a settlement amount to cancel my contract. The settlement amount was very high but i paid it the same day and ask Vodacom to ensure my debit order is stop since I settled the account and when checking my accounts i noticed the debit order was still taken. I am very upset because it messed up my whole finances. I haven't even used the mobile data or phone nr since July 2021