Annoyed with telemarketers

I am getting very annoyed with Chucks cell phone lately the only people that call it are telemarketers. I told this lady that Chuck was overseas and she said that it was a important message to higher his education. Then she said will he be back next week I said no. She was trying to get nosey with me which got more annoying especially when I am walking around walmart. I didnt feel like talking to her and explaining things to her but she was being annoying. Then later some guy called and asked for Chuck. He wanted to know if he wanted to higher his education I said well hes not in then he asked me if I wanted too. I said not right now. Then he asked me which got me really annoyed. I felt bad but I was being a big grump. Then they called back again spoke spanish and wanted to know if Chuck was here and wanted to higer his education. I hungup the phone on her. Is there a way for me to block annoying telemarketers on his cell phone.