I've had two bone graft done for implants on my upper jaw front tooth but both times bon graft failed should i give up hope on implants?

Depends: Depends on why they failed. For the most part if you heal a broken bone, you can heal a graft. Is it the technique? Are you doing something? Meds? Health? Implants will really improve the quality of your life if they can be done.

Unanswered questions: Why did the bone graft fail twice? Are you a smoker? Are there any underlying medical conditions? Is the bony defect large? So many unanswered questions... Hard to advise you without an examination and answers. Please see another oral surgeon for a second opinion.