Is Standard Bank Fleecing their Card Holders?

I was recently late on my credit card payment. The actual electronic payment was made on the due date but it took two days to process so I was hit with interest charges which I half expected. What I didn't expect to be charged with was a so called 'Default Administration' fee of R170.00 which was more than the interest amount. In addition I received two pro-forma emails from the banks card collection department which had no real bearing on the subject in hand. I contacted the card division but talking to the consultant was a waste of time as he could not clarify whether this was a new (or existing) terms and conditions clause. I have had my card for years but haven't come across this issue before. I may be over-reacting but Standard Bank appear to be fleecing their card holders with a double whammy - interest charges and an admin fee. I might be able to accept a significant charge if I was substantially in arrears but the bank received the full payment within two days of the due date. **** poor customer relations!