MTN and some swearing

Loaded airtime last week Monday (5 August) and your system still states insufficient airtime to make a call. My husband has called your call center but you do not want to assist him as the contract is on my name, I’ve called your call center and was told to enter a bunch of codes, restart the phone and pull the SIM card. Still the same problem. On top of this, sometimes when clients try to call him your network reports his number being unavailable. This number is used for business and you are causing loss of business, sort it out would you?