dell inspiron 15-3552 not charging, getting mixed responses

So, just under a year ago I had bought a Dell Inspiron 15-3552 laptop and it has mostly been a reliable and durable computer. However, I've had an issue with the charger (or charger jack) twice now. The first time was pretty straightforward. It was an issue with the jack (had to plug the charger in at a certain position, computer lagged with it in, "plugged in, not charging", etc.) and I got it repaired relatively quickly. But this time around, I had an identical problem (except now the charger has stopped working entirely) but the place that I usually go to for this kinda stuff was persistent about this being a charger issue.

So like anyone would, I went to best buy and bought a charger. Despite the fact that the moron said that it would work with my computer, it didn't (and the fucker didn't even allow me to return it). After that shitstorm, I decided that I'd just look on the dell website for a compatible charger. However, as shown by this ( image.prntscr.com/image/2ab2913161c0448b9d186f2a33b61243.png ), there was no option for an Inspiron 15 3552, leaving me very confused.

TLDR, I need two answers.
1) Is this an issue with the charger itself, or the charger jack?
2) If it's the former, is there any way I can get a list of chargers compatible with this computer?