Will I get a student visa as a Somali passport holder

I have applied to my National visa type D today at the German embassy in London and I came to find out that they don’t recognise my Somali passport. They told me they need to go through a different process to obtain a paper they can stick the visa to and might take longer however that visa will only be valid for 6 months and after I will have to obtain a travel document to issue my student permit. I have been accepted to a German university with a full scholarship so I will have to stay more than six months. The officer told me that my situation is iffy and they don’t know the outcome but will try their best to expedite the process. Now my question is, will this work? I went through a similar situation when I went to college in the UK but that took so long and I missed a whole semester so is this going to be the same? Will I need to get a German travel document to apply for a student permit if I get the visa? Or will the immigration decide that it isn’t worth it and reject the visa all together? Please help I don’t know what to do and this is my last chance in continuing university education.