(1) Both parties must be free and willing to marry
(2) Both parties must have met once in the last 2 years
A waiver can be sought for #2, but it is rarely approved. The consulate must have stated exactly why the denial took place. You need to find that out. Contrary to popular belief, K-1 sponsor and beneficiary do not have to be in love to qualify. Complying with the above 2 conditions is all that is required by law. Ofcouse medical, financial and security requirements also need to be fulfilled.