That's less than 2000 miles, I often do over a 1000 a week and don't have any of this sort of problem, flat tyres excepted, you can get those anytime. Sounds like you were sold a dog ..... take it back, park it outside with a big poster listing all the problems you've had and see if the garage will give you your money back. They may do so in order to get rid of you

Good Luck