Sorry to hear about the hassle you've had :( I had this kind of trouble with a car I bought.

As you've said yourself, when things like this happen it totally ruins the car for you, even if you got everything repaired the experience of owning it would be tarnished. In my case I just traded the car in, trying to get the garage to accept faults and repair them was so much of an uphill struggle it was ridiculous.

Ok update:

It went in for a 3rd go and they made a hash of it they sent me it back to my home with a failed drive shaft (finally found the fault only took 3 goes!!!) anyway they told me when it was dropped off it was safe to drive and I'd get a phone call in 5 minutes it didnt come so I rang and was told to wait a further 5 minutes it didnt come again so I rang again to be told he'd gone home.

The next morning I ring up and am told the drive shaft is faulty having driven it to work already (I work nights) this was the final straw and I took a letter of rejection the next day and am now waiting on the cheque to clear so that I can go and pick up my new car a 59 plate clio :)

Much higher spec than the fiesta I had (except 3 door) and tbh it drove well and it and was about £600 less oh and on my test drive I got 60mpg on the motorway so I was laughing.

here it is:

It's a shame you've been forced to get rid of the Fiesta. They are good cars most of the time, honestly!

Hope you have better luck with the Clio :)