You need to challege the employer's claim.  I suggest that you hire a lawyer to help you deal with the labor dept.  If you went on maternity leave that is not the equivolent of quitting.  Indeed, the work "leave" means that you intend on returning.  I do not understand how he employer thinks it is in the right here.  Again, i suggest having a lawyer represent you here to save your ability to collect unemployment while you look for a new job.