Tracker did not Change Banking Details as Requested now sending me debit order unpaid Messages

I just received 7 messages from tracker stating an installment came back unpaid i changed my banking details months ago and sent the details Through to tracker and everyone that's deducting an installment. Including this the debit order is deducted by tracker on a date they chose4 not like arranged therefore there would not have been funds anyway as i only get paid on the 25th