Amaysim could see takeover offer from SingTel - report, page-7

You forget AYS' strategic value for Singtel which the market cannot exploit and hence does not price in unless a strategic buyer shows up. Singtel as AYS' exclusive MNO supplier on the other hand could unlock substantial synergies through a takeover besides acquiring a substantial market share in an increasingly competitve market, so their valutation will be quite different from your's.
The ACCC action might cost AYS a single-digit amount of milions which would have a moderate one-off impact but no further relevance as the company has already removed the disputed schemes from its portofolio.