There was nothing designer about Mohali or Bangalore. They were just the way pitches are in India. Also SA really got away in Bangalore or this pitch excuse would not be available to them. They kept getting out to straight balls in Mohali and blamed it on the ball spinning. It was not spinning, just going straight on and SA batsmen were shouldering arms only for the ball to then crash into the stumps.
Then they went to Bangalore on day 1, on an overcast damp wicket, Kohli won the toss and put SA in expecting the seamers to take the wickets. SA lost 9 wickets to spinner on even that track to be dismiseed for 215. Nothing demonish about that wicket, as India were 80/0 on the same track. The rain came and saved SA from a hiding, and gave them an opportunity to use the pitch excuse here. Had India steamrolled SA in bangalore which they were on course to do, then SA would have realised just how poorly they play spin, with no pitch excuse available to them.
Its not just here, even earlier they went to B'desh and struggled with spin there. The tests were washed out, but in the ODIs they did, and finished up losing the series. Even here sure this is the biggest spinner of them all, but 8 wickets in one session !! Are you kidding me?
SA fans and team, can hide behind the pitch excuse or accept that they have no played spin well throughout the series, and this pitch just exposed them completely.