I was afk at my iron farm, when I came back I died of fire.
The plots besides my farm where claimed and the wall was replaced with other blocks.
Also the water source got turned into solid stone somehow.
Theory: Someone claimed the neighboring plot and dug down, then placed lava and let it kill me.
They also griefed my iron farms by (illegally) claiming the plots besides it, climbing up, and lava down the villager holes.

Xtjunior has asked me to make a refund request.

What I lost:
Chicken pet

Dia Helmet: Prot 4, unbr 3, respiration 3 and aqua affinity 1
Dia chest: Prot 4 and unbr 3
Dia leggings: Prot 4 and unbr 3
Dia boots: Prot 4, unbr 3, depth strider 3 and feather falling 4

Dia sword: Sharp 5, unbr 3, fire 3 and looting 3
Dia pick: Eff 5, unbr 3 and silk touch 1
Dia axe: eff5 and unbr 3
Dia spade: Eff 4 and unbr 3

And the worst part is:
30 out of 36 villagers where killed in my first iron farm set and in the second set of iron farms 27 out of 37 where killed. So 57 villagers died.

Rules they have broken:
1. Griefing/Stealing

You may not alter any building, plot, or town that does not belong to you without consent. The alterations include but are not limited to:

Placing or destroying blocks
Taking items from any container
Placing or dropping any unwanted items in hoppers
Spawning unwanted animals or mobs
Claiming a plot without the consent of the mayor (Unless otherwise stated in the town rules)
Using your Mayor or Assistant powers to commit any crime
Breaking blocks on your plot, making it look unpleasant before leaving the town

3. Trespassing

Trespassing is the act of entering private property without permission. The plot must have no access with standard permissions unless otherwise stated by signs. Alternatively, a player can be asked to leave and if they don't, it's considered trespassing. To prevent trespassing, one can toggle their town to private or close off their plot with all perms off. Illegal grinder usage also falls under trespassing. The grinder must be closed off and have clearly posted signs stating who is or isn’t allowed to use the grinder. If the grinder is open and no signs are placed, then it will not be considered trespassing until they are asked to leave.
(If you're wondering I have no access signs in and arround my farms.)

4. Settling and Expanding

As a mayor/assistant you are welcome to grow and expand, however here are a few rules regarding settling and expanding:

Btw please dont place the villagers without my concern, they must be placed in very specific spotsCan I please get refunded of the villagers fast?
The gear and tools isn't that much of problem, but without my farms working I don't make any money.