MTN online service not functional

I did an online application for a data contract, automatic response was that in 48 hours I will be contacted. Within 48 hours received a call which I suspect was from MTN which dropped 5 seconds after answering it. Waited two more days nothing, called the call centre I was told there is no escalation mechanism for online application. I was given an e-mail to forward my query. Two after that still no feedback, called the call centre to complain no resolution, sent a complaint e-mail to the complaints e-mail address, I received an auto-response saying “The recipient's mailbox is full and can't accept messages now. Please try resending this message later, or contact the recipient directly.”

Call centre can’t do a new application because there is an existing application which no one can proceed on it. So if MTN can’t resolve this who can???