I've been fitting clifford for nearly 9 years and never had a tilt sensor drain a battery not at those ratings any way. alot of people will point the finger at clifford but to be honest i'd put money on it not being your clifford (unless it's a g3 concept 50(x) this is the alarm that gave clifford it's bad name nearly 10 years ago oh my how things have changed since then in terms of clifford look at the differnce in mobile phones. If a monkey has fitted your alarm they may have put your tilt sensor on the transmission tunnel this is a no go as the tilt sensor is very sensative to heat and would therfore cause you false alarms. the sensor should be placed as near to the edge of the car as possible.
I'd check boot light and kick well lights to make sure they are turning off. All though your alternator is charging your battery my be shagged and will not hold a charge take it to an auto electrician (like me lol) he'll be able to do a slam test on your battery to see if it is holding a charge. If i were to do this i woukd ask for the battery to be charged on a trickle charge for 12 hrs and then stood for 12hrs before i did the test so this may be worth while doing before you take your car there. Shoddy fitted stereos is another one to check easy to test just unplug it.
If you need any more help pm me.
Good luck
P.S don't mean to go on about clifford but i get the arse when people blame clifford for every possible fault on there car when they really have no idea about clifford. Clifford is with out a doubt the best vehical security you can buy.