Standard Bank & Mastercard - technical problems leading to hefty charges

Last month I tried to transfer funds from my current account to my Mastercard but the card had been blocked as I went over the limit and was charged a hefty fee because of a returned debit order - my fault - but if my card was not blocked I could have transferred funds at the ATM and not had an increased debit order rejected due to insufficient funds. Today I tried to transfer again from my cheque account to Mastercard and I get an error message of a 'technical problem - try again later'. I can see another hefty fee coming up as I am unable to pay my credit card the second month! I'm leaving for overseas in a few days and I don't have time to play these games Standard Bank.