I don't care for the ways I have to get my a/c to get cool air

My a/c is the worst a/c that I could ever have, when my a/c works, it is a attractively chilly a/c, then however, it rarely ever works officially; I don’t have a digital control unit, so I have to turn a dial to a colder setting in order to believe it, then last year, when I was using this a/c, I had no concerns with it.

I could set the control equipment to the halfway setting, plus the a/c would make my apartment downright chilly.

I prefer my apartment being cold, so I had no complaints about the lower temperature. When I had to stop using my a/c plus start using my oil furnace, it was with a slight sadness. I liked my a/c. However, when I turned on my a/c this year, it did not work the same way. I turned the control equipment to the halfway setting, plus only the fan came on, as I continued to push the control equipment dial, I reached the ¾ mark, plus the a/c finally came on, sometimes, that setting would be great enough, plus the a/c would make my apartment chilly. Other times, the a/c would make the apartment chilly, however after a while, the apartment would begin to warm up again… Now, I have to leave my a/c at the highest setting for it to run. It makes my apartment unquestionably cold, however any lower setting will make the a/c not run at all. I am not sure what is going on, although I don’t enjoy it, maybe I should purchase a modern a/c.
Geo heat pump