Help with Battery problems please

I bought a new Bosch battery a few weeks ago as the old one went dead and was showing an error code on my trickle battery charger. I fitted the new battery and everything was fine. I don't drive my car at the moment so it has been sat with the new battery for over a week. Yesterday I went to start it but there were no lights on the dashboard and the battery was dead as a dodo. I then put my trickle charge on and it was showing 0.1 Volt. I left it overnight and have just checked it and it is still only 0.1 Volts and the battery wont start the car anymore. All the terminals have got good connections. Anyone please let me know whats going on and how I can sort it out. Will leaving the charger on make any difference in a day or so?
Many Thanks

Anyone?

Sounds like you've got something on the car draining the battery, could be the alternator or interior light/radio or an alarm etc. Best practice is to disconnect the battery when not going to be used/ started up for a couple of weeks/ months this preventing the battery becoming fully drained and possible buckling plates inside battery, if you have no charge from overnight trickle charge then good chance the new battery is now kaput. 
If the battery has a warranty on it, they won't cover it for being discharged by the car electrics, you could though tell them you went to fit it today to find it was discharged before fitting 

Cheers mate. can a new battery be killed like this?

jazman said

Cheers mate. can a new battery be killed like this?

Yes.

Think I would make sure your charger is ok,borrow another one to try

Thanks Gammy Golf GTI for the advise. I managed to blag my way in getting another Battery! Ok So if I have a problem on my car, what should I do now as I don't want it to kill the battery again! Thanks