it is common strategy, it's called farming, they are stealing your resources, I recommend not building any troops, but only activating militia to get them to stop
To build on this, you should build troops and walls. But hide your troops at night and move them in day if they attack. Support another town, hide them in a quest village, etc.
To avoid being farmed to death and maximize your DBP while hurting them, do the following.
1) Activate militia
2) Research city guard
3) Build your farm to 25 at least
4) Get a 10 wall at least.
To maximize their losses, send your troops out in the aforementioned manner. Also, get rid of your resources. Hide them inthe market with an offer only to your alliance, build walls, troops, upgrade a farming village, whatever. Just get rid of them. If they lose troops and gain no resources, then farming becomes less lucrative.
Initially, keep your god to hera. But as your temple goes up and you get more towns and favor. I suggest switching to hades in this town and making cerbs. They are great defensive units behind a wall.
This should kick up your defensive capabilities. Remember that once you max militia, getting a wall and land defense is the most important. Its also smart to use your troops sparingly. Don't stop dodging unless a colony ship flies your way.