OK, update on this trip.
Absolutely zero response from Qantas to email/posted letter and fax.
After 6 weeks lodged a claim with the Small Claims Court in NSW (NCAT).
Surprise, surprise - suddenly was called by Qantas 2 days later wanting to talk compensation.
Was offered full refund damaged case, NCAT application fees and only 50% of original J class fare. After some discussion finally was awarded the actual difference between J and Y class fares on the day. Monies arrived into my account 2 days later.
Needless to say, very much a token apology and no interest at all in addressing underlying issues.
If it would help others progress refunds, happy to supply Qantas ASIC listing for free (this is required for the NCAT application and cost $9-00).
Have just book a Virgin flight, so will be giving them a go for the first time ever this month. This is how you lose loyal customers....