You cannot void the bets after the winner is determined. If you want to void the bets, it needs to be done instantly. These were done after the game was finished.
You can void the bets if the line was an error. This was not an error line.
Well, I don't wanna dig too deep into your case because I don't have all the info. But something tells me there might have been some fishy stuff going on with that betting line, because your betting pattern raises some suspicions. You even said it yourself, "I made 11 pre-game bets..." on that same line, and even more on other platforms. You can't convince me that's just regular everyday betting. Just sayin'! Rollbit casino has the right to cancel or void bets if there's an issue with the betting line. But let's just wait and see what Rollbit Razer has to say about this.