Sometimes,as some have noticed, when you try to collect TTT reward after a de-lorean, there is nothing to collect, your score is --:--:-- and reward amounts to 0 R$.
I've just found a way to unlock this and get the reward. When it is displayed "Finished" and you see your time is --:--:--, just click on back/cancel button before the screen goes to 0R$. You should have come back to home screen. Re-enter in TT, it should say that a new tournament has begun. When entering it, it is displayed again "Finished", but followed by your real time, score and R$ reward.
It works on Android at least.