Neighbor in condo did a remodel without permits. Plumbing is loud

[Angel Co]

Purchased a condo a while ago. No noise problems with pipes. Neighbor sharing the wall did a remodel of bathroom and kitchen (both along the wall) without the HOA knowledge/approval. Pipes are insanely loud now for bathroom and kitchen. Can hear them shower as if they're in my living room. Can hear it through ear plugs!! They didn't pull permits. I asked them to dampen the noise but no response. What can I do?