We have a T-mobile account that has 3 lines included. There was no cheaper plan for just 2 lines, which is what we needed. There are only 2 of us. So, we accept the plan for $120/mo with 3 lines.
Then we decide, if we're granted a 3rd free line, we should use it, so we contact T-mobile to add a friend's number on as that free line.
Cue a week of confusion, issues, problems, phone not working, etc. as T-mobile tries to figure out moving that number from Sprint over to T-mobile. They sent new SIM cards, the cards didn't work, we had to go to the T-mobile store REPEATEDLY, then FINALLY the line is on our account and working.
We realize today that what they DID was add a new line to our account, a 4th line. For $20/month extra. So now we have Me, Gyrf, UNUSED FREE LINE, and Friend for $20 extra... for the past 5 months as well