Monthly Coterminous appointment

I am appointed as Monthly coterminous employee which was approved by our office and attested by the Civil Service Commission. Before I grabbed that monthly coterminous position, it has undergone the right process. The item position was published and so I applied and luckily was appointed. However, months after my appointment (while waiting for my salary, almost three months) I was informed that my position was unavailable, unfunded and the posting of the said vacant position was a clerical error. And so my appointment was void as they said and it has to be dissolved. Was it really a clerical error? In fact other regions have the same item also. So why can't we have the same? We are of the same agency. I doubted there is something in it that works to my disadvantage. I felt disappointed and discouraged despite the good performance I had. I want some advice on what to do with this. I felt helpless.