Problems with vehicle bought 2 months ago

I bought a secondhand car from Toyota Bruma in June 2017. I was assured that the car was in perfect working condition, very well looked after and that a full service was done just before I received the car. However, I have recently had the car breakdown twice in traffic and the car is making a very loud squealing sound when I drive. I brought this to the attention of the dealership a week ago and they indicated they would get back to me as soon as possible.I also requested the contact information for the Roadside Assistance that I was told came with the car. I have not heard anything from them since. I am a pregnant woman, driving alone - I cannot have such an unreliable car and would definitely not have bought this car if I knew it would be giving me such serious problems 2 months later. It leaves me as a customer feeling like I was conned into buying a lemon! I will be taking the car in for a full Dekra assessment and I will be submitting that report along with my complaint to the NCC and MIO.