eight-wicket thrashing by Australia in Colombo on Sunday night.
"It's hard to put my finger on it. We started badly and finished badly as well. So, there is a bit of a bad taste in my mouth."
The formidable Proteas have often being ridiculed as the perennial chokers of international cricket, having failed to win major a world title since their return from an apartheid-era ban in 1990.
The pattern has remained the same in the ongoing tournament where South Africa lost both their Super Eights matches to hit rock bottom in group two which also features India and Pakistan.
Their fate hangs by a slim lifeline, with the side needing to beat India by a huge margin in the last round of matches on Tuesday and hoping Australia deliver a similar treatment to Pakistan.
"It's not all over yet," the captain said. "We are not the kind of team that will give up quickly. We will come back and try and improve, we will have to improve."
South Africa have looked jaded after being on the road for three months, having flown to Sri Lanka from an arduous tour of England where they took over as the number one Test side in the world.
They pinned Pakistan against the ropes in their first Super Eights match when, defending a modest 133-6, they had their rivals reeling at 76-7 before allowing seamer Umar Gul to turn into an unlikely batting hero.
Gul smashed two fours and three sixes in his 32 off 17 balls, sharing a match-winning partnership of 49 in 27 balls with Umar Akmal as Pakistan romped home in the final over with two wickets in hand.
Against Australia, they were pounded with bat and ball by in-form Shane Watson to crash to their second defeat on a slow pitch at the Premadasa stadium.
Watson claimed 2-29 and then smashed 70 off 47 balls as Australia restricted the awe-struck Proteas to 146-5 and then surpassed the total in the 18th over.
South Africa never recovered after left-arm spinner Xavier Doherty justified his recall by removing Richard Levi with the third ball of the innings and sent back Jacques Kallis in his second over.
Watson admitted he was surprised how South Africa continued to flounder in big events.
"Every tournament we go into, they've got an unbelievably strong side," Watson said. "They've just got an amazing amount of talent.
"I'm not exactly sure why they can't seem to really perform at the big events over the last 10 or 15 years. Because the quality of players they have, they should really be dominating."
South Africa's strategy in the must-win game against India will be plotted by coach Gary Kirsten, who made a name for himself by coaching the Indians to the title in the 50-over World Cup last year.