You have three choices:

1) Get a Masters Degree and do really well so that you can apply for a PhD on a Great School.

2) Work as a technician for 2-3 years at a good school and try to build a solid research background and then apply for a PhD.

3) Apply to a lot of schools and think about Top Tier Schools after your PhD.

Regardless, you still can do a lot better if you do well on your GREs and taking the subject GREs might help a lot as well. 

Good luck!