Transaction declined due to insufficient funds issue

<p>Absa's Mastercard transaction, time and again embarrasses me as a client, when I do have sufficient funds on my card, but still declines the transaction. Ive taken it up with the bank, yet they keep doing this. Apparently around the 18th of the month they add their interest. Problem is that often this cause an out of funds situation. I understand this, but what ****es me off, is when I do make a payment, they still decline transactions in the next 24 hours. They cannot explain this to me. I know it's a system glitch or sonethibg they programmed, yet they refuse to acknowledge this as a flaw that causes customer dissatisfaction and embarrassment. I am now looking for a another bank. </p>