NO TAP WATER. Try watering carefully from the top with rain water or distilled water. Keep them in a sunny window or under florescent lights.

I've seen these kits & my nephew bought one. Question is - did you follow the simple instructions that came with the kit? One important rule is that it needs stratification when planting them in the growing media. Stratification is giving them a cold treatment to simulate their environment. usually done by keeping them in the refrigerator for 4 to 6 weeks. That simulates winter period & once you put it in a warm sunny place, that simulates the coming spring, stimulating the seeds to sprout.

I have a feeling you didn't read the instructions since one of the rules clearly states to water it with distilled or rain water, but clearly states no tap water. That was the first mistake you did.