i don't really like this rule that if a match is abandoned or canceled the bet is void, on other betting sites there are other rules(maybe better?) but since they are written clearly we have to accept them, we can also bet on ufc / mma events?...

Of course the bet will be void. The game is already canceled so it is normal that the bet will be voided and return to the gambler. It is just not normal if the bet will not be recovered by the gambler. You should report this on the support of the gambling website if you are really having a problem into this.