Ginge,

Circumstance has worked against you here. If you had been stopped during the day, this would have been cleared up with a simple phone call to the insurance company.

The officer(s) who dealt with you at the time had no other option but to seize the vehicle - according to the motor insurers database, you were uninsured.

The responsibility lays here with you. It's your car, so you have to check all the documentation which relates to it is correct. I expect you'll have no joy in complaining to your insurane company either, because when the certificate and other bumph was sent to you, there would have been a line written somewhere similar to:

"Please check that all documents are correct, otherwise you may find that your insurance is void and that you risk prosecution" or similar.

You're most likely going to have to pay the recovery costs and chalk it up to experience.