NBN plans specifically exclude CSG delays in connection now but I take it you are on legacy HFC cable?
Can't figure out if you are eligible for compensation. For one thing its doesn't apply to internet services (only phone). The CSG legislation is byzantine at best. So many ifs and but clauses. Seems to me there is an allowance for up to 20 days delay in new connections).
Anyway I'm no lawyer so see how it goes. The Optus CSG page is here. I do remember reading how nuts the process is. Basically there is no claim form. Optus will review your connection and automatically apply any CSG compensation as needed. This process may take four months. Its not one you have any input into.
After 4 months you can ring the number (that's hidden on the link above): 133 937
I suspect you'll be told no review has been conducted but maybe I'm being cynical.
You had me spell checking "compensation" 🙂 I do love words and it was a blow when I eventually learned that using the exact right one often had the opposite effect of communicating what you mean.