How to get mould out of fabric? ?

Just took my sons playmat out of storage fir our next bub who's due in June, and it has mould on it! I've soaked it in diluted bleach wash and that's freshened it up heaps but there's still mould - any other suggestions? I would rather not buy a new one as this was over $100 and not used for long, it's a fisher price rainforest one