Convenince store managers say that they are told how much they must sell by the company, and (there are even stores that say the amount to sell to part-time workers) / (there are even stores that say the amount for part time workers to sell).
The article is talking about how student workers are complaining about sales targets for 恵方巻.
I'm not sure about the last part. What does アルバイトの人に売る数 mean here? Does に mean to or for? Does the shop have a quota for selling 恵方巻 to its workers. Or is it a quota for the workers to sell? How can I know?