The hosts were closing on a series-levelling victory but De Villers said they should have made an official complaint about the incident in which England bowler Stuart Broad appeared to stand on the ball during the third day.
South Africa raised concerns over the condition of the ball with match referee Roshan Mahanama but the International Cricket Council issued a statement saying there was no evidence of any wrongdoing.
"Climbing on the ball with your spikes is obviously not on," De Villiers told reporters.
"We'd all like to get the ball reversing and swinging all over the place but it must be done legally. I thought we did make an official complaint because (coach) Mickey Arthur said he had sent an email through.
"There should have been an official complaint because the ball clearly started reversing after Broad stepped on it and you could see a piece of leather was out the ball.
"It was a bit naughty, I'm not saying Stuart should be banned or anything but it certainly deserves to be looked at," De Villiers added.
NO ACTION
South Africa manager Mohammed Moosajee said the team had accepted Mahanama's decision that no further action be taken but but still believed the condition of the ball had been altered.
"We are satisfied and will not take the matter further but we were concerned about the condition of the ball as early as the 15th over when it started to reverse-swing," he said.
"We looked on TV and we could clearly see the ball had been altered, whether inadvertently or not, we left that to the match referee. But there was an indentation on the ball and marks that went across."
South Africa, who set the tourists 466 to win, had reduced them to 132 for three at the close and De Villiers said they were optimistic about completing victory on the final day.
"We're in a good position, we're very close to making it 1-1, but it will take a lot of hard work tomorrow and all the boys are prepared to put in the hard yards," De Villiers said.
"The wickets of Kevin Pietersen and Andrew Strauss were the key for us, we know they can score big hundreds, so to get them out was massive. It was the result of good bowling and good pressure."
England opener Alastair Cook, who made 55, said the team would take confidence from recent draws they have secured through rearguard batting efforts.
"We'll take a lot of confidence from the situations we've been in before, like in Cardiff and the first test here, and we have fighters in the right positions," he said.
"The pitch has held together quite well but we have to make sure we don't lose wickets in clumps," Cook added.
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