Terrible service and exorbitant charges!

I've had an account for more than 12 years. Always I use the 6 month payment option, as there is no interest on this option. I've struggled specifically in Feb & Mar to update my details online as to receive my accounts via email. It took HOURS - doing it myself and calling the call centre various times. Even updating it via the call centre. It still hasn't been updated. I purchased items on account in Feb around R684. I started receiving sms'e to indicate amount due, which I have been paying. Cut to today, where I look at the detailed statement and notice: R2.80 charged per SMS R20 charged for a phonecall Interest charged at 16%?! This was done per month to date?! WHEN did your policies change to charge for SMS'e and interest on accounts if paying within 6 months. R20 a phone call?! After your terrible service and now THIS on my account, I'm closing it. The lack of transparency of these extra costs, shocking service with regards to online buying and updating my details has brought me to this. Stop spamming me with your calls too. This is the first time a brand I've been with for so many years has caused me to feel so much disgust in a period of 4 months?!