When parties ask a Magistrate to make a decision to resolve the disputes they have in a divorce or child custody matter, there is almost one person who feels they lost. More likely, but parties often feel that they lost. Resolving custody disputes by litigation takes the power away from the parents and places it into the hands of a Magistrate who doesn't know your children. Despite this, sometimes litigation can't be avoided.
If you feel that the Court did something wrong in your hearing, you will need to file a Petition for Review of Magistrate Order. The deadline to file this depends on how your Magistrate entered his/her ruling. If an Order was issued in the courtroom from the bench and issued a "minute order" (which looks like a print screen from an old DOS computer), your deadline is 14 days from the date of that order. If the Court issued an Order and sent it to you in the mail, your deadline is 21 days from the date of that order (beware--the date of the Order, not the date you receive it!).
In your Petition, if you want to argue that the Magistrate made a mistake in her factual findings, you will need to order (and file) the transcript. Otherwise, the reviewing Judge must conclude that the facts supported the Order issued by the Magistrate. With a 14 or 21 day deadine, you must Order the transcript right away - and pay the premium for a rush delivery; otherwise you may not have the transcript before the deadline. If you end up not having the transcript in time, you can ask for an extension of time to file your Petition for Review - but there is no guarantee the Court will grant it so you should do your best to prepare your Petition for Review and ask for permission to "Amend" your Petition once you receive the transcript.
When filing a Petition for Review, you can either argue that the Court got the facts wrong or that the Court applied the law wrong. Factual determinations are hard to overcome because there is usually some basis in the testimony of the hearing to support the conclusion drawn--you just may not agree with that factual conclusion. In other words, you have to have a strong case that there was no evidence (or insufficient evidence) which would have allowed the Court to establish a fact. For a question of law, you will need to provide statutory or case law that contradicts the law the Court applied or statutory or case law that demonstrates the Court applied the law incorrectly to the facts of your case.