After service lost in ifinity

I bought a vw tiguan from them on the 6 the of june 3 days later the engine managment light came on. I had a full diagnostic report done which revealed 11 faults. 2 of which are seriouse the alternator not charging properly and startex not working properly either. Luckily diagnostic warnes one ahead of time. I informed them after which they simply said i had test driven the car and a bought it at the advertised discounted price. No where was it communicated to me that i would only get help from them should there be a problem if i paid full price. The discounted price was also the excuse used why they would not replace back tyres which had non tread left, do the change of ownership of put any petrol in the car. I had to do all this, so the could assist with nothinh. As i understand the law clearly states a car can not be sold as is by a dealer and i have logged a case with the ombudsman please think twice before purchasing a car from these guys. Poor survice from the sales staff to begin with oand obviously no after service worth mentioning