Poor customer care by MTN

I received a call from their agent about an upgrade on the existing contract and I subsequently initiated that upgrade. I received a payment link which has expired since I couldn't pay within it's timeframe, as I didn't have enough funds. I tried going to a store at Easgate mall to revive and complete the order but was told it can only be completed online since it's an online order. I then wrote them an email, to which Nokuthula Khoza responded by requested my ID number. I supp**** the ID number promptly via email again, but everything has died down. Their call in customer care is frankly useless. I'm losing my patience and soon I will cancel the existing contract and never continue with an upgrade.