If you were written out by someone with the legal authority or right to change the terms of the trust, you have no recourse: trusts (and also wills) may be changed so long as they are done so by the person(s) with the legal power to do so, subject, however, to the following: 1) If the person making the change was not mentally competent when they did, the change is not valid;2) If the person was threatened or coerced into making the change, it is not valid; or 3) If the person who made the change was tricked into it ("fraud") in some way, it would not be valid.If you think that 1) - 3) applied, you could challenge the change with a lawsuit in chancery court to enforce the original terms of the trust. Or, you could sue if 4) you believe that the change was not done by someone with authority--or that there was no circumstance under which the terms of the trust could have changed (e.g. it was an irrevocable trust). In this case, too, you could bring a legal action to enforce the original terms.So if you think that one or another of the above-referenced problems exist with this change, you should speak with an attorney about your legal options (e.g. about bringing a lawsuit).