1. Yes, you can force the large company to take down the images until the monies are paid. However, you will first have to serve a notice of repudiation of the settlement agreement you entered into which provided for immediate payment. Essentially, a settlement agreement is like any other contract. Once accepted you are bound by it until you repudiate it due to non performance of the agreement. So you must first repudiate the settlement agreement on the basis of non-performance and immediately direct them to take down the images. You can then bring injunction proceedings if necessary, to force the shutdown of the website whilst it contains any of the images you have copyright over. In future, you need to have an "Unless" clause in your settlement agreement whereby the images are to be taken down from a certain date "unless" a sum of money is paid. This ensure that you are not left "hanging in the wind" as has happened here, where your images are being used and you have received no money.
Please RATE the answer positively so that I may get paid
The other side produced an open contract that referred to all of my images and we wanted this changed to only the images being used by them this I understand was acceptable
but they have not paid
sorry for the delay could have a look at my reply