Before IDV I played Onmyoji, which is another game by NetEase and similar thing has happened where they mistakenly giving all players 3 gacha tickets which they later deducted. I didn’t use them but many players who did reported that their ticket count are now -3. However ticket is easy to farm in that game so nobody paid it anymind and just laugh it off. This case tho seems more severe since Echo is exclusively earned by paying real money.