Where those stores actually hiring? Don't worry, its quite usual not being called, but every time you try you have a chance to suceed.
When someone is offering a job depending on the requirements and market situation they might get lots of applications. (For example my company currently offers two jobs, one about technical stuff one about translations. For the technical thingy, just few applications and no one really good - for the translation thingy, we got spammed with applications).
When applying to stores, its probably jobs that dont require special skills, so probably lots of people think they could do that and apply.
If you want to get a call, first thing is to not do any formal mistakes (like spelling sth wrong or flaw on the paper). If someone gets lots of applications, they might sort out such which mistakes first, without even looking closer at them.
Next thing is to convince them youd be an interesting person to employ. For some job at a store it might be a good idea to stress that you are good at calculating and good at dealing with people. Having a CV that shows this is better than just telling.
It might also be a good idea to have contact before sending an application. If some shop is hiring, you could for example go there first and just ask if the job is still available. This gives you a first chance to present yourself in a rather informal atmosphere. A later application from you will be less anonymous then.
That comes later. And I don't think there will be very elaborated interviews for some college part-time job.
I've written some advice here, might be helpful for you too:
How did you get your job?