Experience with 'Autism at Kingwood'?

Hi, I'm new here but in need of some reassurance or possible redirection.

I was referred to Kingwood (OAADSS) earlier in the year by my GP, ultimately for an autism assessment. 

I chased the referral this week after not hearing from Kingwood. They say that they never received it and that I'll need to start the process again, therefore advised that I look at the self-referral option.

I have a few qualms with the NHS for other recent matters as well as this, but I'm wondering what experiences others have had at Kingwood? Is it worth my time? 

I don't really have the finances currently to go private, but I don't want to force myself though any trauma even if there isn't a price tag.

Thanks