Constant problems with Galaxy s4 sim card

[edwardofcpp]

My s4 has had a problem with the sim card for months where it would not be able to detect my sim card. I would randomly get a "sim card not detected" popup, which then forces my phone to restart. After searching online, I was able to find a temporary fix of shoving a piece of paper in the back to apply pressure on a certain area. This made the restarts less frequent but still didn't completely solve the problem. I was satisfied with just this solution, but just yesterday, my phone did the typical sim card restart but instead of the phone loading back up normally, I got a "emergency calls only". The phone detects my sim card (since the notification bar on the top doesn't have a simcard crossed out indicating that it's not detected), but it's saying no service even though I'm hovering around 3 to 4 bars. Specifically, when I open the phone and have the password lock screen come up, I have a (No service) right above the Emergency Call button. Is there anyway to fix this?

Booting in safemode doesn't change anything, and I already checked my IMEI on tmobile's website and it said this:
Congratulations! Your device is ready for use. Select one of the SIM cards on the previous page to get started.

 

[B. Diddy]

Welcome to Android Central! Have you tried contacting T-Mobile for a replacement SIM?

 

[hubermania]

Try rubbing a pencil eraser over the brass pads on the SIM card. Then go to a T-Mo store and get a new SIM card.

 

[edwardofcpp]

Nope, I can't until the weekend. I was thinking this was a problem with the actual phone itself and not the simcard, since applying pressure to the back of the phone helps the phone detect the sim card.