No one gts back to you

After my payment went up end of January I queried and was told I was put into a higher income bracket. The wrong amount was submitted. I got a new letter and mailed it on the 10th. I received a read receipt. On the 12 & 13th there was problems with the phone lines. Called yesterday and was informed no such mail was received. After numerous phone calls and having to resend the mail, the problem has not been resolved. One person says 24 hours and the other 3 Days. So once again I must pay an extra R1180. Then my optometrist phones, my medical aid is suspended. I have not received correspondence. They posted the letter. The post office is still having issues delivering all the post. so no mail, sms or phone calls and not once was I advised of this since my calls from the 10th. The payments goes off via Debit Order, so because they made a mistake I have to be punished. I refuse to make this payment cause they have to rectify the problem. When I ask to speak to someone superior I get put back in to the waiting line for the Call centre and have to explain everything once again. Or I get told they can't phone out, having problems dialling out.This is unacceptable.