Charger Won't Work Unless I Twist

Hello,

I have had my laptop (I don't know the type, so I attached a picture of the system information) for 2 years now, and ever since day one, my charger won't work unless I twist and push and try a bunch of different positions. I have tried to fix this numerous times, but I have had no success. I bought an off-brand charger the first time I tried fixing it and had the same problem (had to move around the charger for it to charge my laptop), but it eventually stopped working altogether and I contacted the IT support/geek squad and they told me to buy another charger, but the same one as the original.

So far, I have had 3 chargers, and all do not work. I thought the problem was with the plug-in socket, but they wouldn't check it. I also thought that maybe the battery needed to be replaced or taken out, but mine isn't removable and they wouldn't try anything else but telling me to buy a new charger... again. I'm sick of this. I just want to know what the problem is and how to get it fixed, at this point, I'm considering never purchasing another Dell product ever again. I can tolerate one faulty charger, but 3 of them not working makes me think the real problem is the laptop.  

I would appreciate any help/thoughts on this as I am desperate to have my laptop actually charge. Most times, the light goes on for a little second and it says that the charger is "plugged in" (doesn't charge but doesn't die), other times, I try and try to get the charging light to come on to no avail. Please help. 

Thanks,

Lauren