******* deduction from my bank account

I sold my vehicle about two months ago, I contacted Netstar to cancel my account, the account was activated in 2011 so my actual contract was not binding. Netstar continued to deduct payments from my account, I contacted them today and they said due to the fact that they couldn't get hold of the new owner they didn't cancel the account and kept on deducting money from me. This is blatant theft, how can anyone trust a vehicle recovery company when they ***** money from the client.