No. BE a pest. I've been on both sides of the desk. I've always taken a second look at people who have followed up and kept in touch with me, reiterating their interest in working for me every once in a while. You wouldn't believe the number of FLAKY applicants I've had to sift through, how many people I THOUGHT for sure were gonna get through the orientation, FTO priod, etc until they just flake out. Your gentle tap on my shoulder (figuratively speaking) may just come at the right time. Sometimes a good person who applies falls through the cracks. It happens. It doesn't mean my HR is slagging. It just means we get swamped with a LOT of other stuff sometimes and occasionally hiring-which takes a lot of time-has to take a back seat unless there's a sudden demand for more services that threaten to overwhelm my resources. A lot of times when you haven't heard back from someone it generally isn't that you've done anything wrong. It just means the employer doesn't have an immediate reason to talk to you-and that can be anything, justifiable or not. Sadly, a lot of HR folks these days don't take the time to communicate with applicants all throughout the process and afterward (even when not selected). I know some companies go through DOZENS of applicants in a week but that's no excuse. A quick email may not mean much to the person doing HR but it means the world to an applicant-who is also VERY busy because his/her job at the moment IS looking for a job- and it takes just a couple of minutes to do. I remember back in 80s I drove all the way up the coast from LA to Crescent City-near the Oregon Border- to interview for an ambo job. It went really well but then I didn't hear back from them and I ended up having to call them 2-3 weeks later to find out they'd already picked somebody else. I felt like crap. If someone makes that kind of effort, and he/she interviews well, you bet your top dollar I'll AT LEAST have the decency to make sure they're called back in proper time and informed that someone else was chosen for the job and thank them for coming in. Respect goes BOTH WAYS. Sadly, it's not given by a lot of these private companies nowadays because they're so focused on the bottom line. These aren't just "applicants". They're EMTs and Paramedics who are medical professionals and they are PEOPLE. Like the people you care for in your rig: they're not "calls". They're patients. Even better, they're PEOPLE.
Hang in there. Keep trying.
That said, "part time" or "per diem" in Los Angeles County is kind of a dead thing. A lot of ambos find it easier and cheaper to hold over or call in FT staff than it is to maintain a staff of PT or PD folks. Remember, the backend of HR is the whole hiring process, orientation, FT, etc and that can be expensive and time-consuming
If you want part-time, or per diem work that pays nicely, check out the events staffing companies.