iphone 5 hands free stopped working on my Nissan Juke after oil change?

My iphone 5 hands free stopped working in my 2012 Nissan Juke after I took it into dealership for an oil change. I could see calls coming in on the car display screen and the call connects but caller can't hear me and I can't hear them. I took my car back to dealer and left my phone and car with them for a full day but they told me it was an iphone issue. I tried removing and adding my phone again but it hasn't helped. I can still hear music when I connect the phone w/ the usb port. Anyone else have this problem?