If you can deal with LA7s, you need some training. Ask the trainer about ENERGY, and you will learn the ways to keep out of the sights of LA7s.
The LA7 is fast, but if you retain your energy, you can get out of it's range even with planes that have a slower top speed. LA7s have a small ammo load, and they have cannons. They are not going to be doing much spraying at long distance, so keep out of their range.
You will mostly find LA7s in close defence of an enemy fields at low altitudes.
If you hate them so much, take this information and find a way to hunt them down and kill them. This is a game.