My attorney told me that I'm paying too much child support, 630 dollars monthly and he said that I have to pay just 500 $. He did the appeal but already past more than a month and haven't received any answer, he told that I have to wait for 90 days . It's true? I live in ny.

You have a lawyer and you come to the internet to get your question answered? Do you have some reason to doubt your lawyer?

Yes ,cause I had like 3 weeks calling him and he didn't answer until I told his secretary that I want my money back.

He callled me and told me that I have to wait 90 days but I don't believe it.

Normally in most courts all that happen is the judge reviews the paper work filed showing the change in your income.

Normally it has to be about 3 years ( in my area) unless there is a major change in income.

500 dollars is a little high for just this filing, but not out of hand.
And yes taking 90 days in today's over crowded courts would be fairly quick in some places

But the attorney gets the money even if the court says NO, unless he gave you a momey back promises ( and they don't)

So if he filed the papers and the judge refuses the modification, the attorney still keeps the money you paid

Courts don't move too fast. If you are concerned with that your attorney is doing what he should, then check with the court to see what's been filed and when a hearing is scheduled.

By the way, are you and your current girlfriend sharing this ID?

Often, again at least locally here, there is no hearing, the judge merely requests income statements and makes a ruling unless you specially ask for a hearing.