2106215696 / 210-621-5696 Reverse Phone Lookup

This phone number is my mothers phone number and she gets calls from every state and people are being rude to her telling her she has been calling and harassing them all day. this isnt true because my mother works all day at a hospital and hardly ever uses her cell phone. she told her phone company and they said they couldn't do anything about it. how can someone else be using her cell number calling all over if she always has her phone 24/7 with her??? it doesn't make any sense. i wish it would stop because my mother is getting very upset with people calling and cussing her out for something she's never done.