The Mexico international has struggled to establish himself at Spurs since joining from Barcelona in 2008 and has made just 10 appearances in the Premier League.
"To be honest I already felt at another club, Sevilla, and we had already completed more than 50% of negotiations," the 22-year-old told Sport.
"Almost everything had been agreed but with half an hour to go Spurs changed their minds, something I found very odd.
"I hope this time he is honest and tells the truth when I talk to him about where he would like me to play.
"Both myself and my agent have been left disappointed, sad and angry at the way Tottenham have acted and after such a long time without having any confidence in me I am now going to get my chance, which seems strange.
"Even so, I mean to take this opportunity out of respect to the Tottenham fans and also because of the professional I am."
Dos Santos has been included in Spurs boss Redknapp's 25-man squad which has been submitted to the Premier League for the first half of the season.