Feel like I got used by a hiring company

I’m currently job hunting, and last week I did a take-home design task for a software company. The hiring manager gave me great feedback and said she’d talk to the director about moving forward.

She had been super responsive up until then. But once I followed up about the offer… silence.

Now I’m starting to think they never planned to hire me and just wanted free design work. It sucks. I put in hours of effort, energy, and hope for literally nothing. Anyone else ever go through this?