I think you need to discuss the result with Dr Wong directly, preferably meet him in person, as people can be evasive on phone/email.
He is an excellent surgeon and I wouldn't doubt his ability.
I am not an expert but I from my knowledge and experience; I do not believe the number of grafts used would have given you the desired result unless you had exceptional hair characteristics.
The problem is that people see someone who is in a similar position to them from videos/pictures and think my result can turn out exactly or nearly the same as patient x.
Unfortunately it doesn't work like that with hair transplants, honestly I wish it did.
Failure of the hair transplant to grow can be caused by other factors e.g. physiological factors and sometimes may not grow with any identifiable cause.
This is why hair transplants are a risk, even in the hands of an excellent surgeon.
Even the very best surgeons will have poor results, but they have far fewer of these than anyone else and the proportion/ratio of good to bad will be very high.
I am sorry to hear this as 15000$ or whatever you paid for is not the sort of change you find down the back of the sofa.