Hi Guys I have a Mazda CX-5 13 plate had nothing but issues with it for the past 2 years

I have had an error message appear saying DPF inspection required.
Used redex dpf cleaner, didn't work
Took it to Halfords for a DPF flush £89 they said it didn't work and told me to take it to a Mazda specialist, I called them they want £140 just to look at it.
I don't want to keep throwing money at it does any one have any ideas how I can fix the issue, could it be a sensor if the flush didn't work?

its on finance so I cant return it either or sell it.

I also have issues with a noisy fly wheel and an error code for a turbo underboost , one of the worst cars ever!

 

I would book it in with Mazda for diagnosis.

 

I think I might have to, I have booked it into a garage close to me, see if they can diagnose it first if not Mazda dealer it is