Bad service from Dealership as a whole

After service is horrible or should I say non existent. Bought a vehicle Early September. I had to take it myself to Dekra for roadworthy in the first place. Almost 12 weeks later (3 Months) my vehicle is still not registered. Tried calling them to speak to dealer Principal and sales manager but he is always out or busy for the last 8 weeks I am trying to reach him. Still do not get any valid reason out of them what is taking them so long to register this vehicle which I am paying for which is not mine in actual fact.