This is quite rare but can certainly happen. Do you live in a humid region or near the ocean? Do you keep any acids or oxidizers in your shop like black max? I keep mine outside.
The punches are a high carbon tool steel so they are more prone to rust but should not be rusting at the degree you’re describing. I have found this product to be most effective and is not a petroleum based product, which I have health issues with:
https://www.amazon.com/Fluid-Film-TPAS11-Penetration-Displacement/dp/B00B93ZXGS/ref=sr_1_5?dchild=1&keywords=lanolin+anti+rust&qid=1594677252&sr=8-5
I also have used this before, more for firearms though:
https://www.amazon.com/Break-12-Ounce-Cleaner-Lubricant-Preservative/dp/B003THLBYU/ref=sr_1_5?dchild=1&keywords=breakfree&qid=1594677376&sr=8-5