Miway call centre harassment

My daughter is being harassed by Miway's call centre. They phone her up to 8 times a day. She blocks the nr and they phone from another number. She asked them to stop phoning but they keep on harassing her. She is a student, she doesn't even have a job, but they won't stop. I called them to ask them to stop and they said they can't remove her nr from their system.