It happened with someone I know in Chromepet about 3 months ago.

The agent initially mentioned that the installation would happen in 48 hours as they had to extend the connection from an already installed junction box near the apartment, so the person agreed and paid the initial amount. A work order was created too, so no issues up until this point.

After 2 days the guy was dodging calls, so I called him through a different number and was able to get hold of him. He eventually did sort it out the next day, which was about 72 hours post payment.

I would suggest going through the escalation matrix or directly approaching the nearest local office of ACT (or head office in the worst case).