And well, it's nearly impossible to proove the opposite despite players experience. The game will frustrate you to spend money. Rigged matchmaking? I know of "food" clans specifically set up to lose to "boost" main clan accounts. Ofcource DON'T take my word for it.
5.3 Rigged Matchmaking - Experiment
The game company has a patent on their matchmaker, and in a legal case the workings were disclosed to be as you thought.
And the same goes with no BB's once in a while. Have now got 1. This could be one person with a very low win rate, but that is unlikely because of what I said above.