Greenhouse haven kit

DaisyLMAO​ I've had an issue like this before. I had 2 kits that kept uninstalling. It's an Xbox problem rather than a Sims problem but I had to check in Manage Game and Add-ons before playing each time and see if the box was checked next to all of my packs. So I'd recommend doing that before you play each time. You could try uninstalling and reinstalling the whole game and also check that your Xbox is up to date. Eventually the problem stopped for me but by checking before playing you don't run the risk of having items lost from your builds. It's unlikely to uninstall itself once you are playing, I've never heard of that happening. Xbox support just told me to reinstall each time but they weren't sure why it was happening, they said it would stop eventually and indeed it did. 

If you've repurchased it by accident that's a matter for Xbox support here's the link.

https://support.xbox.com/en-GB/contact-us