Marked absent for a module that I have proof that I submitted!

I have been marked Absent for a Teaching Prac because the lecturer was unable to open the file. I was not given any feedback or the chance to resubmit the module. I have now qualified with an incomplete degree because of this. The lecturer has done nothing to rectify nor has the department given me anyway to correct their system. In desperation, I have signed up for this module again - but I am now working and this will be impossible. When I eventually do get through to the call centre - the agents always say send an email to your lecturer - but the lecturer is the one, whom I believe 'stuffed up'. Is there anyone that can give me answers that make sense?