What Causes Discomfort Followed By Painful, Red And Swollen Neck After Insertion Of Picc Line In Arm?

Hi, I had a picc line inserted in my left arm 7 weeks ago. As the picc line was inserted I felt a small discomfort in the front of my neck, just above where the rib cage finishes. This pain grew and became quite painful,becoming red & swollen during 6 weeks of chemo. The doctors prescribed antibiotics at first, then decided it wasn't an infection so turned to ibuprofen. Which at first seem to help, but not for long. Now I'm still in pain, more so at night in bed. The doctors don't seem to know what is causing it, can you help with this problem.