In fact, it would be difficult to find an industry that does NOT have old fashioned whips and chains slavery in it's supply chains somewhere, and if you use the SANE definition of slavery (any instance where people do not have the realistic option not to work for this specific employer under whatever contract that employer chooses) then frankly there are virtually none left. 
The only cases where you don't find it is in small business - and even there you can't count retailers since you'll certainly find it in some of the products they are selling.