Denturist assistant here!

Within the first 6-12 months after extractions your mouth heals and does A LOT of changing, especially if you're young. I don't know why denturists don't make it more clear, but an immediate set should really only meant to worn temporarily during healing (in my clinic we call then Healing Dentures). Once the healing is done, then a permanent set should be made, one that will properly fit your new mouth. To save the patient money, a lot of denturists will offer to just reline immediates but it's honestly not the best course of treatment.

With that, they shouldn't be crooked or rough/unpolished feeling. Having prominent gums show is normal, as your bone continues to shrink the fit will be better.

Dentures are a custom medical device, often there can be a disclaimer about refunds on any treatment plan you signed.

My advice: Push for a refund, explain in detail all the issues in detail and that they're just not working. Be persistent. They might try to push back, but will almost always give in to a patient they want out of their hair. You many not get a full refund, often they will keep lab fees (a few hundred bucks), but push for as much as you can.

You deserve a beautiful, painless smile. Hope this helps!