Tracker *****ulently repeating debit orders on a canceled contract of a vehicle sold over a year ago

Sold my vehicle over a year ago, canceled the Tracker contract, spoke to the call center, emailed and they continue to debit my account *****ulently on a monthly basis, they change the amount for the value to go through as I've reversed several debit orders and stopped the debit orders. Very ***** business practices. I'll pursue legal action