Bad treatment by the dealership on car registration and sharing purchase contract

I purchased BMW X1 on the 20 July 2018 at BMW dealership called Supertech Durban. Dealer adress is 8 Cliff Crescent, Cnr Bellair Rd and Solomon Mahlangu Drive,Bellair, Durban 4094. I was promised that the car registration will be sorted with 7 days. so far my car registration is still hanging a month after the purchase. when i call the sales executive, Mr Nkosi Tembe who assisted me when buying the car but he no longer takes my calls. i called him on the the landline and found him and he promised to call after 2 minutes but it never happened. this is so unprofessional. Everytime i enquire i was told it will be sorted within a week until the salesperson ceased taking my calls. During the purchase BMW promised to email the contract. i'm still waiting to no avail