would like opinions please

So I’ll try to make this quick but I am honestly looking for some opinions..

We are a family of 4 and we have 2 children, 2 and 5. A few months we moved into an apartment, they are called luxury apartments and they’re new, they aren’t cheap by any means but when I viewed the place twice there was families everywhere with dogs and it just seemed like such a sweet place to live. I was extremely focused on finding a nice place with good amenities for the kids and the leasing office made it seem like it was so kid and family friendly.

day 2 of living here we were still moving a few bags inside and my fiancé was coming home from work and i was cleaning and rearranging. Our neighbor rang our door bell (we are 2nd floor) and my fiancé answered, the man said we were being way too loud and it was ridiculous etc. My fiancé apologized and explained that we just moved in and were trying to finish up some things and the man left. they live below us.

Week later the leasing office puts a friendly reminder on our door to respect our neighbors and to remember to be quiet. It states “neighbor complains they can hear your kids waking and playing and running on the floors and it’s all day” now mind you it’s all hard wood floors here. At this point I am angry because we just moved here and I can’t help if they can hear my kids walking or playing.

I talk to the leasing office and they assure me all is well and they just wrote that to appease my neighbors and I have nothing to worry about.

This month I received a hand written note from my below neighbors basically saying that my kids are obnoxious and rude and they can hear them all day long and we’re disrespectful etc. (this is all during covid lockdown) I can’t go anywhere with my kids. I called the leasing office and they assured me something would be done.

this week I received another notice bout my kids being too loud and playing with their trucks on the floor and dancing around.

What does one do? I am in a 12 month lease and I really want to move but on the other hand why should I let someone run me out of my own home? My poor kids basically are tied to their chairs or couch because they’re nervous to move, I feel like a prisoner in my own home anymore and it’s depressing. It’s not cheap to live here and we’re only 2 months in. We don’t play loud music, tv or have people over it’s just regular day to day noise from families in my opinion but what would you do?