Thank you for contacting JustAnswer.
I am sorry to hear about the problems you and your husband are experiencing. One thing to remind your husband of is that even if he had not been divorced his daughters might not want to spend a lot of time with their father at this point in their lives, particularly if they were told that they had to. Instead of forcing the contact, it may be much more effective for him to work on giving the girls unconditional love, to have an honest discussion with them about what they need from their relationship, and to try to find activities that the girls might enjoy (either individually with their father, or together). The more he shows them unconditional love without pressure, the more likely they are to feel more inclined to have a relationship with him. He might try reaching out to them in the form of upbeat texts, calls or notes, just to let them know that he cares, but not to make them feel guilty about their lack of contact. If they are willing, going out for dinner together, or fun activities could help to build bonds through more enjoyable activities together. A good book about dealing with divorce is Helping Your Kids Cope with Divorce the Sandcastles Way http://www.amazon.com/Helping-Your-Kids-Divorce-Sandcastles/dp/0679778012
This book gives helpful information about what his daughters may have been experiencing. It may help him to understand them more easily.
I hope this answer is helpful. Please let me know if I can clarify further.