Question about water irrigation/sprinkler system

Mostly who to call to get answers.

I'm going to tell what is going on, and list the efforts I've made thus far.

I moved to my new home in mid August. 3 months ago.
It has an automatic sprinkler system that covered the back yard, and the small front area. Although it's a house it's part of a condo community, so the HOA fee covers the water for common areas. I just pay for my own personal use.

First thing I did (within the first month of moving in) was to have landscapers come out to take up the grass in the back yard, lay down landscape fabric and cover with gravel and a few large boulders. No interest in maintaining a back yard.

I was told, and verified during the process, that they were going to cap off the sprinkler heads in the backyard, so no water flowing.
At the time I did find it odd they didn't go into the gararge and actually turn off the backyard. I honestly had never looked at the timer myself. I'm not mechanical at all. There was paperwork clipped to the timer I later looked at but that's kinda where my problem lies.

The water meter is read around the 7th of the month.

In my previous residence, a house of similar size, and more land, the normal usage of water per month was about 1200 gallons. In my final months there, when alone, it was even less. Let's call it 1200 gallons a month.

I wasn't concerned about my first bill as there was an overlap between the 2 houses, and for some of that time the irrigation system was going in the back. I was however, surprised that the amount was 4000 gallons. I figured it would drop the next month.

Nope, next month was 4000 gallons also. To me that's appalling. The billing cycle that's ended but haven't been billed for was for 3500 gallons. No way in hell is 2500 gallons being used for a tiny patch of native perinneals and some grass that runs along one side of the front walkway. The other side is driveway.

I called the utility company and they sent someone out to check there were no leaks. There were none.

Brought it up with a few neighbors, but there's was the same, as they are using the sprinklers.

I called my realtor, who asked the previous owner (at least I asked her to ask this) how many gallons a month he used. He wasn't really helpful, just saying "I never had any problems"
I'm not going to try to get him involved again. He's moved on.

At this point I'm guessing the sprinklers weren't capped off properly, so I pulled down the timer paperwork. I had watched a youtube video on how to shut off different zones.

The problem is I cannot tell from looking at the map of the property where the different zones are. Don't know how many zones, or where each one is.

So. I called the landscaping company and explained. I asked if they could send someone out and explain it to me. I don't mind paying a service call if that's what it takes. At first they said "sure, we'll send Juan, our lead landscaper out, and he can make sure the backyard is shut off"
When I said that I needed a tutorial so I could do it myself in the future, it turns out English isn't Juans first language, and my Spanish isn't good enough for anything technical.
They then back off and said I should call the manufacturer, which is Rainbird. I looked on their website, called their 800 number, and essentially got no where with them. I'm not surprised. It doesn't seem they would send someone out to explain a 5 year old system no under warranty to me.
They did give me the email of the area sales manager. I haven't sent an email yet because frankly, I am not confident I would get help about my particular backyard layout from them.

I guess I'll email them, and I'm thinking I'm also going to call the landscaper back.

Hm... thinking about it, the landscaping office is only a mile away. Maybe I'll take the paperwork over there and someone can point out the zones.

But anyway, besides that...

Who would I call for something like this? It might seem like a no brainer for some people, but this isn't someone I know anything about.