I am so happy - the points finally came in - I received another phone call from Qantas today to check on the situation.
No points had been deposited - however while I was talking to the consultant they came in!
I just got the last J seat on the LHR-Sing flight and we are now seated together.

A question - we are both on different booking references - I will ask to be linked together - is there anything else I need to do to ensure we are seated together?

We have seats now Sin-LHR and LHR-Sin in J - however we will have to travel with economy baggage restrictions as the flights Per-Sin and Sin-Per will be a paid economy seat ticket. They will also be separate booking references.
We will fly on the same day Per-Sin and Sin-LHR with a five hour gap in transit ... however on our return it will be LHR-Sin - which arrives at 6.40pm - the flight to Perth is either at midnight or the following evening.

Any advice on the Per-Sin return flights? I would ask for the booking references to be linked on the outgoing journey.

Qantas have been fantastic - the girls all very enthusiastic to help - Jetstar Mastercard not at all.