Just think about it for a minute:
If you were an HR recruiter and the person you just hired is ALREADY unhappy with the position you gave to them and is asking about getting a different one, wouldn't you be perturbed, too? The fact that you are just going to leave the current position at the first opportunity will necessitate her having to go through the entire process of reviewing applications, conducting interviews, making a billion phone calls, and hiring another person. If someone were making more work for me like that, I'd be peeved, too.
No, the place wasn't completely upfront and honest with you, which sucks. However, beggars can't be choosers. If, as you say, you want to be "bringing home more" money, find a full time position. If you only want casual hours, look for part-time; that's what it's for. Financial need is going to out-trump the "coolness factor" of a job every time. If, in the future, you are offered both part-time and full-time jobs and you need money, pick the full time one!! And full-time doesn't necessarily equate inflexibility (if you are going back to school or have other commitments); you could easily find a job working three 12s a week or such. If you don't like your current position, move on.
There are plenty of long-term care facilities that would hire you in a second. Yes, we all know that you are a medical assistant and that you want to use the skills you learned in class. But if you want to do those medical assistant skills, then work as a medical assistant! Working as an aide will get you nowhere quick (in that respect). Outside of working as a medical assistant, there a few if any jobs that will let you do the hands-on skills that you are looking for.