Company called "My Phone Bill". They claim that they are collecting information on behalf of the telcos, such as number of/type of phones, usage, internet speeds, your current provider(s), how satisfied you are, name of person responsible for phones, etc. I think that they are data mining and then selling your info to the telcos.

I tried calling the number back always 'busy'. Heard lots of noise in the background though and people talking on phones, dead giveaway.