When did you buy?
OK. How much did you pay and how old is it?
There is no realistic chance of recovering the full amount paid I'm afraid. Come what may, you have received the benefit of this car for two years and there would be a reduction in any refund to reflect that. The law clearly allows that.
However, this was a relatively expensive purchase and a newish car. The number of repairs are not acceptable.
At the very least a like for like exchange is due.
If that is not acceptable or not possible then you could ask for a refund but there will be a reduction to reflect your use from the vehicle unless, of course, they are willing to agree more than that.
Can I clarify anything for you?
Remind me how long ago you wrote to them?
Well, you cant force them to reply.
If they refuse to engage then your only option is to sue.
It is not likely to come to that though.