I own and have used many of them for decades without problems. My friends, family and I have put tens of thousands of rounds down range with RamLine magazines over the past 30+ years
The spring works backwards. It unwinds as the follower travels downward. Think of a metal tape measure and you will have the idea of how it works. That is how they get 2-3 extra rounds in a flush fitting magazine
The design was so unique, that it was granted a US patent in 1987:
US4888899A - Magazine for housing cartridges using a spirally wound conforce spring
- Google Patents
Without pictures it is hard to tell what is wrong.
You should be able to remove the base plate and manipulate the follower from the bottom (I know, they are crappy base plates). Make sure to have some oil in there as well to aid in your un-sticking efforts.
I have these for Walthers, Beretta, SIG, Rugers and Smith and Wesson. Not to mention the ones for my 10/22s.
The rimfire ones are pretty cool since they are double stack. The short ones hold 30 and the full length ones hold 50. Plus they can be jungle clipped together. The 30s are my favorite for prone shooting.
The Company was basically forced out of business by the
Violent Crime Control and Law Enforcement Act of 1994 or more commonly called the Assault Weapon Ban
90% of their product line was legislated away. I know the name has been resurrected, but it is not the original company. They do still make the stocks.
I have never heard of them refereed to as "jamline" before today. Tonight I even Googled "jamline" but got zero hits in the first five pages