http://www.missinghorsesonloan.co.uk/ click on "information needed" on the left and their posters are the last two. they have been stolen/missing for over a year now. both mares are micro-chipped.
so sorry to hear this , but I think microchipping only proves they are yours when they turn up , freezemarking is better as they can be identified and are more difficult to sell on hope they turn up x