you have my sympathies for the lost cargo bug, i'm now taking plenty of screen shots at key points in case i get hit. if i need my account fixing by support i can then get exactly the right amount put back on.
as to the docking problem you may not realize it but it's actually very good news as you have learned two very valuable lessons early in the game.
lesson one is always check for the blue pad assignment notification that sits just above your radar when you are about to enter the docking tunnel. if its not there don't dock, hit full reverse and back off to give you time to make a docking request.
never ever fly without a cash reserve, even if it means buying cheaper, less profitable cargo. the bug is partly to blame here for robbing you of so many credits but you still made the error of overspending.
imagine if you hadn't learned this lesson now: fast forward a few months and you have now put 100 hours into the game and are flying your brand new anaconda for the first time, you spent ever credit you had to fill her with cargo and are just coming in to dock. Kaboom: 100 hours progress flushed away.
how mad would you have been then?
now, because of the hard lesson you've had there is no chance you will make either mistake again. when you do lose your next ship, you'll have kept enough in hand for both the rebuy and some working capitol to get you back on your feet.