I was promised two weeks work on one site, with pl...

I was promised two weeks work on one site, with plenty of work in my area to follow. The facts are/ On arriving on site and starting work the Site Agent told me I would only be needed for three days tidying the site prior to a visit by the company Chairman and the agency was aware the contract was for only three days.Having sent all my relevant details to Think Recruitment and doing three days hard work its ELEVEN WEEKS LATER and I still HAVE NOT BEEN PAID! regardless of endless phone calls and plenty of empty promises.