This is unclear, because the facts presented don't confirm that the employer's filed labor certification was approvable at filing. More information is needed. It is unclear whether you have proof that the labor certification was filed or that it was approvable at filing based upon what is written.
I strongly recommend an appointment or teleconference with an experienced immigration attorney.
The above is general information and does not create an attorney client relationship.
Most likely you are covered by section 245(i). Denial of your Labor Certifrication due to failure to respond to a request means that the case was (most likely) approvable at the time of filing (* unless the request had to do with questions of fraud in the application or the case). You should also be prepared to demonstrate that you qualified for the position at the time it was filed and that you were physically present in the US on December 21, 2000 (Lease, pay stubs, W-2s, utility billls etc.)
245(i) only serves to allow you to adjust status in the US by paying a $1000 penalty fee if you are not in valid status and/or worked without authorization. However, you willl still need a valid immigrant visa to serve as the basis of your green card case. There are a host of additional issues to consider before filng any case. A comprehensive evaluation of your options is advisable.