I'm getting really hacked off with this game, I'm getting to the point where I hardly ever win because the moment my men start a fight they put their guns away and charge the enemy. WTF?
That's called Sabotage
Your weapons are being sabotaged by an enemy Saboteur which make them useless and have to change weapons or if they don't weapons left, they go with hand-to-hand combat against the enemy. You should avoid fighting against Saboteurs from the time being if your troopers aren't high level since most of their weapons can get sabotaged. Here is a Forum where you can ask for help at any time.