what waneqa said is not true. IF you take bad care, it evolves into different characters it would evolve into when you take good care of it.
I suppose you wait some more time and give your tama the chance to evolve, what I personally experienced and i don't know if it's true for other gotchi users is, that it takes longer for the tama to evolve, when the training points are not high, but again, that could just be happening to me (or be a glitch or something)
If it is that what xyou meant waneqa, I am sorry to have said you were wrong, but if you meant it wouldn't evolve at all, you are not right and i don't want to pass on wrong information to users looking for help