Poor service

It's been 3 months since they've stopped debiting my account or sending me statements and invoices. However, they keep sending me SMSs that my account is in arrears. I don't understand the notion behind this. I have on countless occasions, phoned and emailed them to debit my account but they're not. Now I must constantly call, get transferred from pillar to post for invoices and make manual payments. It's becoming ridiculous.