It will depend on whether the electronic time of submission is taken as the assignment submission deadline or the physical submission. Universities warn students that things can go wrong and that unless it is a catastrophic failure, the deadline is the deadline.
Submit your mitigating circumstances in writing, using the correct process for your university. If once your work has been considered, you are at a grade boundary as a result of the 10% reduction. They may consider your mitigating circumstances. If it makes no difference to your grade, it will not be considered.
It won't help you now, but if someone experiences submission problems, the best thing to do is call the department before the deadline, a minimum of 1 hour before, explain the problem. If you cannot get through, e-mail your assignment to a lecturer or the departmental email address - this gives you a time stamp and submit the physical copy on time.
So basically you left your work too late to be completed/ submitted, tried to do so in the last minute, there was a technical error leading to you not submitting something else on time and now you're angry and trying for an appeal? Isn't it your own fault (you knew there was little time and common sense tells you that complications may always occur when you need them the least), why didn't you just hand in everything earlier?
I'm not trying to be rude, but you can't seriously expect them to change their decision when it was obviously your own fault?