Qantas seat selection for Platinums in economy vs business class

Wondering anybody can give some advice. I used to be platinum but don't travel as frequently these days and therefor have simply gold status. However when I travel I pay for a full business class ticket on all domestic routes I use. Why is it that I can't never select a seat in the first 3 or 4 rows of the business cabin as they are greyed out no matter what flight I take and no matter how many weeks ahead I try to make my seat selection. I understand this may be the reserve of Platinum flyers but I find it very frustrating that on several occassions I'm placed in the back of the cabin and chomping down a rushed meal on a fast sydney melbourne route or told my meal preference has run out, only to find a whole range of passengers in front of me have paid a discount economy fare and simply upgraded. I'm paying a full service business ticket and always placed behind these people in the seating order. I have no problem with the people in front of me, good luck to them. Its just I pay full fare for certain flexibilities that are implied by QANTAS but not delivered on. Has anybody got any ideas how to get around this?

Seat selection for Qantas for all unreserved seats generally opens up 72 hours before the scheduled flight. You still may not get seats in row 1 or 2 but you may be able to snag something forward of what is released for Gold FF status at the time of booking

Not much of a way around it, it's just the nature of tiered loyalty. It can be frustrating but then if they didn't have that perk for P, attaining it would be less attractive and lucrative for QF! 

Thanks to all for the good advice.

T minus 80 hrs should be the time you get to pick a better seat. If you can, set yourself a reminder to jump in a select a seat as close to that as possible for a chance closer to the front.

I've travelled in row 1 before, never again, it's too noisy! It's like sitting in the galley. Mind you, I accept that your question wasn't asking me to put you off, was it?

Paid J PER-JFK in Oct 16 for travel in Jun 17. At the time of booking row 5 forward on the PER-BNE A332 flight showed as being blocked. (16 of the 26 seats available for sale) On the upper deck of the 747 BNE-LAX flight, row 14 forward showed as being blocked. ( 10 of the 14 seats available for sale )  Qantas call centre advised that seats further forward may become available closer to the travel date. Travelled J PER-SCL in April 2014 when a similar situation was experienced. Being retired, and self funding travel at a frequency not able to attain or retain status seems to place us at a disadvantage to those travelling with corporate funding and often with a cabin upgrade as a result of status. Surely a situation would never occur where blocked seats would preclude a cash sale.

I understand the point that if you are paying full fare, then you could expect to choose a seat, but on the other hand, a P1 flyer is spending north of 200 hours a year in a Qantas tin can, and that makes them a pretty high value customer.

Having just made Platinum I wondered if there was any additional benefit above QFF Gold when selecting seats, or does the 'magic' T-80 still rule?

There is a APP named "T-80 for Qantas" in the Apple Store which very easily calculates the T-80 time for you.

You need an App to work out when T-80 is????