Cancellation of 24 month contract

My contract with you guys ended in January however you are still sending me invoices for payments . I spoke to two consultants , one in December advised that I would automatically be cancelled in Jan when my contract ends . I don’t understand why you guys are still billing me on a contract that has ended , you are breaching your own contract and if this doesn’t come to an end I’ll escalate to the ombudsman. Please don’t renew or anything , just cancel my contract .