Generate leads for cleaning company

we are a firm of cleaners and need someone that can compile a list of small/medium sized companies in london, call them, give them some basic information about what we do and get the name and contact details of the person in charge of their cleaning contract for the potential leads.
The names and contact details should be then passed to us so that we can follow up and try to close the sale.
I'm indicating a Per Hour budget but this will need to be tied with a minimum number of valid leads generated Per Hour of work.