Worst after sales experience

Bought a car via Private to Private Finance, which they required me to license my car within 21 days. 21 Days are long gone and have received no forms from them that they mentioned, they must send me before I can license the vehicle. 21 days over, no forms, after countless emails and no assistance from anyone else within the department. Still waiting for my email to arrive that I was told last week I will be copied in to, apparently. I can't license my vehicle without details that I need to put on the ALV form.