If I find something to bet on live, the max bet is MAXIMUM 0.0005 mbtc.
It's not even 1 mBTC? That's too low of course. Why they would limit such a small amount of max bet? By any chance, are you betting with the BTC which betja have given for free? Just asking. If you have deposited BTC, then why would they make it so small max bet?
Max bet amount become limited for some users based on their betting activity. They have also reduced my max bet limit on live matches, and I was playing with my deposit. Probably their odds provider has done it as I have won most of my last placed bets in live matches. But my max bet limit is higher in most of the pre-match betting section.
By the way, can we make multiple bets on the same match?
AFAIK, none of the bookie allows the user to place multiple bet in the same match. But you can place a single bet on those double winnings option which has been mentioned above by Little Mouse.