Unfortunately, we can’t take away your old mattress, but we can recommend 'Soft Landing,'.
They service a select number of regions around the country and are a great social enterprise where you can organise the collection of your old mattress all online. As well as being convenient and affordable, they prioritise hiring people who struggle to enter the labour market and recycle up to 75% of the mattress components.
You can find them here: https://www.softlanding.com.au/.
Alternatively, if your current mattress is still in relatively ok condition (no stains/tears etc) reach out to your local Salvation Army, they offer free collection to re-home your mattress to someone in need. This may be a service they can offer in your area.