Who called from 7807021495

I have had a few calls from this number to my work voice mail. There is nobody on the line but I can hear voices in the background. It sounds like a business/customer service environment. I would like the calls to stop. Thanks!

Stop calling my cell in Ottawa

sick of this number calling me and i called back and it says number cannot be completed as dialed?
STOP CALLING ME PLEASE

female phoned and asked for me (first name used) and could hear other female in background giggling. Person on phone also giggled.

some kind of charity asking for donation.