dealing with aggressive neighbours

So there's a lot of context probably required for this one, but the tldr of it all is that our neighbours are vindictive and aggressive and I'm at the end of my tether.

so for context - about two years ago, these new neighbours moved in next door to me and my Nan. It's a couple, and their two kids. From the day they moved in, we haven't had a single day of peace. Either their youngest (12-13y/o) is running around the house yelling at every hour of the morning, they're whistling all day, or they're in the garden playing football. Now, the football is the biggest issue and the reason we're now in a sticky spot.

I'm incredibly noise sensitive, so any sound tends to set me off and I try and deal with it with noise cancelling headphones and earplugs where I can, but they kick their football so hard against the back fence that it really does sound like someone has set off a gun or thrown a large rock at something and tends to break through whatever measures I'm trying to take. We also have a dog, and she hates the sound too and will immediately go out and bark at them anytime they start to kick the ball. She can also bark at them when they go to their outdoor bin, that they've chosen to place underneath our front window, rather than in their side-alleyway, but we're always, without fail, trying to get her back inside or to quieten down.

Also worth noting, she is an anxious dog, and her response to anxieties is to bark but despite this, she isn't actually very loud most of the time. If there's a fox in the garden in the evening, our neighbours are kicking the ball against the fence or at their bin, or someone comes to the door she'll bark, but other than that she is fairly quiet, even when we leave her for a little while (we have a puppy cam for her).

Fastforward those years to now, and yesterday everything blew up. We've been putting up with the sound for so long, and yesterday when my dad was visiting he called out to the kid to 'give it a rest' when he started kicking the ball very hard and very loud, while we were all trying to talk in our own garden. The man from next door proceeded to start yelling at us over the fence, claiming we were being aggressive and harassing, and that our dog barks all day every day and they never complained. This isn't true, for a start. My nan lost her temper, but I later went and tried to mediate (also over the fence). Their solution, apparently, was to tell us that we were being unreasonable asking them not to kick it so hard, as it wasn't our fence they're kicking it against, and just weren't listening when we were trying to explain it was the noise, not the damage. He then started yelling at me saying that I need to take our dog out when they're playing football if she's going to keep barking, and when i said that wasn;t possible, he said "well then you need to put her down." While all of this was going on, this fully grown man was once again pelting the ball against the fence, proving a point. 

Today, i recieved screenshots that the woman from next door had been posting on her facebook about how we were c***ts and complaining for nothing, and about how we abuse our dog, claiming we never take her for walks. While she isn't walked every day, there are reasons for that that are none of our neighbours business anyway, and she's never home to know one way or the other. So effectively, she's spreading lies now all over social media claiming we're being unreasonable, and also saying they'll get more people around to play more games of football, and are planning to have a loud party. 

I am honestly at the end of my tether. I have no idea what to do. I don't think we're being unreasonable in wanting to be able to enjoy our own home in peace and quiet, and were even offering to help pay for a solution like padding for their goal and were told to *** off. I dont know if it's just my brain not understanding how they can be like that, but i feel so lost and so fed up and I really, really don't know what to do. The council don't seem interested, but the thought of putting up with months of music and football and screaming (when I'm also about to start a job with night shift work), is making me sick. They've already started today with playing music loudly, and trying to goad our dog into barking.

P.S it's 11:20pm now and they're in their house shouting to one another through the walls. I have a white noise machine and it does nothing, but I can't sleep with headphones either. I really just want to cry.