Hi Simone23,
I think if I remember correctly I had this happen the other day, in my game while I was playing my gardening game. My Sim people had glitched - wouldn't harvest/tend but one plant.
I was done with the particular lot at the time anyway, so I thought I'd have them move. They couldn't use the phone to move. I thought maybe it was just the Sim person's phone. So I placed a phone on the wall, and had another Sim person try to use the phone to move and that didn't work either.
I just ended up clicking out to edit town, and clicked evict family. Deleted them, as I had them saved them back previously. And then saved the lot.
I don't know if any of this will help you, but just wanted you to know you're not alone.
MrsFlynn