Tracker charging existing customers 40.8% more

A tracking unit stop functioning properly in about March-May 2014. Tracker advised the client in Nov 2014 and the client discovered that not only did Tracker know about this for months and kept on debiting its account, but also that the 2x 8 year old units are being charged at 40.8% more than two new units. The agreement was cancelled in Nov 2014 and the subsequent debit order which became a double debit order to add insult to injury was reversed for knowingly not rendering a service while charging. Tracker continues to pursue the last installment (30 day notice period) and is now apparently taking legal action!!!