Xiaomi UK store deliberately preventing returns/refusing refunds

I was a big Xiaomi fan until I ordered a phone from the official UK store that arrived broken. I notified them the day it arrived and was fobbed off 4 times over the phone arranging a return for refund. After each call no returns envelope came. On my 5th call I eventually got a returns envelope and I sent it off. 1 week later I got it back still broken with no explanation and then thereafter they said I had no rights as the 30 day return period had expired. The whole process felt like this was deliberate to prevent a refund return. No more Xiaomi for mi. Anyone else have a similar experience?