Redundancy pay problem. Should overtime pay be included? Woolies woolworths

Okay Will keep this short

Worked at Woolies for 12 years. The last 8 or so I have been doing regular overtime.
I am contracted for 20 hours but have ALWAYS done 39 (an agreement that was made and was never reviewed)
I got my redundancy pay but it was only for the contract hours. I have scoured many sites that say if "overtime is part of weekly routine" then I should get pay based on that over time
Is this right?
I don't want to waste my time on phone calls to the already busy sector dealing with Woolies claims, if I have no grounds for this claim.
A lot of people think I can get more money.
Would appreciate any tips.

Dear Rag Doll

If you believe that your contract was varied to 39 hours in a verbal agreement but not in writing, then make this representation during consultation.

Regretfully, if no one can back up that you believe a variation to your contract was made on the basis of an implied change, then they will go by what your contract of employment states.

Worth fighting and see if you can get any evidence or statements to make your case. However, with Woolworths being in the hands of receivors it is going to be difficult. Cant your manager verify this?

Best wishes and good luck

Carol