604-460-2500 is Lighthouse Realty in BC. If you went to their website looking for homes to buy or sell that is how they got your number. Or at least that is how they got my number.
This is a real estate call back service. Although they are based in BC, they serve all of Canada. If you left your contact information on a real estate agent's website anywhere in Canada you may receive a call from this company on behalf of the agent you contacted. In our own situation, my wife left our contact info on a Century 21 website in Saskatchewan and these people called back to follow up.