Tuscan Mk 2 battery not recharging-HELP!!

[smd]

Help!
My Mk2 Tuscan had a flat battery that wouldn't charge up.It was replaced with a new one last thursday-70 mile drive.What happens when i try and start it today-flat as a pancake.hat should I look for first.Alternator probs?.I'd be greatful for any help asap
cheers

[2 sMoKiN bArReLs]

Simple (ish) things first: could there be anything (interior light) etc that could be draining the battery?

[smd]

Can't see anything.I've even left alarm off.Only light flashing is immobilizer.When put ignition on,battery charge is reading 12.1v,but not even turning engine over