Where is Pinterest Corporate Office Headquarters HQ 

Dear Pinterest,

I’m wondering how well you vet the companies you allow to advertise on your site. I have made two different purchases through your site in which the seller has taken my money yet failed to deliver the purchased product. In asking what recourse do I have for either receiving the purchased product or a refund of my money. I’m 63 years old, disabled and on a fixed income and with the economy as it is, every penny counts. Please advise me on what actions need to be taken in order to receive my product or my refund. I look forward to hearing from you soon.