I upgraded to the s5 Active and then had to return the phone because people with iPhones couldn't text me. I had ordered this case, but obviously don't need it now. PM me if you want it!
They can text you, if you still want to get it. My BFF moved to an S5 and we had issues at first. People with the iPhones basically have to do all the work.
Make sure they delete the original text thread, then have them resale your number under mobile and to make sure they're not sending to your email/Apple ID.
It also takes a couple of days for the system to catch up.
I already switched to the iPhone 5s. It was way too much of a hassle. Thank you for trying to help though.