Sorry can't help as apparently it's your fault for not notifying them.
During your MIA period, do you still get paid?

Let's hope that the other company didn't find out about your "short" stint. If I'm the boss and I came to find out my staffs did "this stunt" on another company, I don't think I would have any confidence in him.
Anyway, always think as if you're in the other shoes. i.e. now, it's your staffs who go MIA on you.

Yeah...usually it's not worth the time and money to go all out against these guys. (I mentioned usually but not necessary they don't)
But it had been so rampant nowadays. The last I remember one poster posted that he/she doesn't want to attend the first day of job after agreeing to work......

Kids nowadays!!!

Who in the right mind would go play MIA with companies without first notifying them?!...oh....got .... only you
Btw, forgot to mention; they actually have the right to strip you from your current working company as I believe in every employment letter signed, there's a clause which says that you cannot be employed under another company while under the service. That's what fyrie meant by "Technically, you're should be in violation of your current contract with your current workplace as well (my assumption, based on the fact that most contracts do not allow u to hold multiple full time jobs at the same time, and your previous contract is still in effect).".
So you better take care of it fast before they file a suit against you.

What's so difficult?....Call up and appologise.