Negligence WRT client services

Account gotten into arrears, paid up to date, received several SMS's stating that the account is not up to date and handed over, follow up was made with Cartrack, they confirmed it was an error from their side which they will resolve immediately, a week passed and I received another sms stating the same meaning the matter did not received the necessary attention which Cartrack assured me it would. Seriously considering to cancel my contract and move to another service supplier as it is clear Cartrack is not all about service and have enough clients that it will not have any impact on them should I take my business elsewhere