I had my braces off about 3 years ago. I noticed my upper teeth slant out straight away after I got my braces off. I want to complain to the doctor but my mum said that it's too late and nothing can be changed. Recently I've graduated from my secondary school and I wish to fix my teeth(only 4 upper slant out). I only wish to fix the four teeth. It is still OK if I go back to the doctor to complain after 3 years? If I'm going to have a second braces, do I have to pay again? The time I got my braces the payment is about 3,600, but now it is 4,000 . Oh my! I do not expect to pay such a huge amount. Is it possible tat the doctor won't charge me?

You should have brought this up to the orthodontist long ago... but I still think that you should get his opinion at this point. Get 2-3 orthodontist's opinions of your situation and go from there based on the cost and the reputation of those giving the opinions.

I don't know that any professional can "guarantee" results, especially after time has passed. It's possible an active-type of retainer could help, but you will have to be very compliant in wearing any type of removable device. I agree, get several opinions.

I would say that first is it really that bad, or is your merely your opinion, sorry but I see this with people that do plastic surgery all the time, no matter how good, they still don't like it.
And if the doctor saw it was still off then, he would or should have keep correcting it. ( unless mom and dad no longer wanted to pay for more adjustments and so on)

And with braces, teeth may not always be perfect, they only improve them to some point. I have even heard of some teeth moving back slightly after correction without follow up.

So you needed long ago to go back. If you want to go back, then get parents to take you back and find out. He may do more corrections at a discout ( but I would not hold my breath) most likely there willl be new charges based on what type of allignment is needed.