Tuna short in tin

I recently started a new diet and one of my meals call for 120g shredded tuna in brine. I had bought tins of tuna from Woolworths the Woolworths brand and net weight is 170g with drained weight at 120g. This was perfect for me until I opened the rim and drained it to discover there was only 88g of Tuna drained. I have photos if you would like. This is not on Woolworths. Already we pay a premium for your branded products and you can’t even give me the tuna I paid for...