No-one bothers to respond to emails

My account was in arrears, however I never stopped paying, I only paid a smaller amount which I intended on settling when i could. I received a call to make a payment arrangement for a specific amount which I duly paid, but not before I got a legal letter. I not only paid the agreed upon amount, but because I managed to get extra money, settled my account in full and in fact paid R 300.00 too much, which now appears as a credit on my account. I can however not use my account and no-one bothers to respond to emails. So you can call me and threaten me with lawyers even though i never actually stopped paying, just paid a lower amount while I was having a hard time, but when i want to use my account, i cant use it? I want a response and this to be sorted out ASAP. It is nonsense.