verizon to sprint number mix up

Okay the tech guys couldn't figure this one out. Maybe some other users have this problem. I have had my phone number for around 5 years now with sprint. When one particular friend calls me with my number programmed into her phone, it will randomly call 1-800-my number. She is a verizon customer btw. She went to verizon and checked the phone records and it showed that she was calling my number, not the 1800 number. She changed her phone and her number and it still calls him occassionally. This wouldn't be so bad if it was a business but it forwards it to this old man's number and he yells at her every time. The only thing i noticed on my phone under advanced phone info is that the channel changes back and fourth from 350 to 375. MY little brother also has this problem when one of his friends calls him.

 

hmmm, but since its in their systems as calling my number, wouldn't that by my phone carrier's problem? they said on my friend's end that everything was working correctly.