MTN Totally ineffective at resolving simple issue sof or receiving invoices

I have been a client for over 20 years. Following a recent upgrade six months ago I no longer receive invoices and statements. I have spoken to the representative and call centre multiple times and they are completely ineffective. No Response from - Rorisang Moumakwe Representative: Enterprise Client Service - Contact Centre C: +***3 Regina Naidoo Representative: Customer Service C: +***9