Dear Customer, I am sorry to learn of this matter.
You can file a complaint with the State Bar, the Bar will investigate the matter and potentially take administrative or disciplinary action against the attorney. (They will not take any steps to recover your money for you).
Unfortunately, this probably isn't enough money for a legal malpractice attorney to be interested in (the complexities of a legal malpractice case - see below - are simply too great to warrant pursuing a case of this value on a contingency fee over). However, you can try mediation. Contact your local bar association and ask for referrals to mediators, a third party neutral may be able to help you reach a mutually agreeable resolution with your former attorney and avoid the time and expense of litigation.
Legal malpractice cases are based almost entirely on expert testimony. You must not only find an attorney to act as an expert witness regarding the standard of care for your prior lawyer (to prove the "negligence" elements of the case), but also an attorney expert (and potentially other experts) to testify regarding the underlying claim (you must prove that absent the attorney's malpractice you would have achieved a better result - often termed "the case within the case").
Due to the complexity of these claims, I highly recommend that you retain a legal malpractice plaintiff's lawyer (also called trial attorneys). Fortunately the majority of these attorneys will provide you with a free consultation, and many will represent you on a contingency basis (they will advance the costs of litigation and legal services in exchange for a portion of your successful settlement or judgment).
You can find local attorneys using the State and Local Bar Association directories, or private directories such as www.AVVO.com; www.FindLaw.com; or www.Martindale.com (I personally find www.AVVO.com to be the most user friendly).