If this issue (or any other) winds you up as much as it does me, I would recommend using some of your self-righteousness to write a letter to your MP. How I did so is enclosed below.
Dear Kate Hoey,
You may recently have read in The Guardian about Sports Direct's policy of keeping all of their part-time employees on zero-hour contracts.
I feel like zero-hour contracts are unacceptable, as they leave employees with no sick pay, holiday pay or guarantee of future earnings. This sort of security is something that I feel an employer should provide their employees with.
I would appreciate hearing your thoughts on this matter which I consider very important.