A debtor can dismiss a chapter 13 at anytime. However, the best course of action would be to contact a good bankruptcy attorney to review your situation and provide you with options. You do not need to dismiss your case in order to change attorneys.
I agree with attorney Tucker. However, before you seek to dismiss your case, you should consult with another attorney. It is not necessary to dismiss your case to change lawyers. In fact, any dismissal would have to be filed by your attorney of record. If you want to stay in the Chapter 13, your attorney has to file a document called a Substitution of Attorney. Get it signed by you and the new attorney and file it with the court. Good luck.
A person always has a right to voluntarily dismiss his chapter 13 case, but you don't need to dismiss your case in order to change lawyers. You could very well have the original attorney sign a substitution of attorney form to sub out and have your new attorney sign to sub in. If you are having issues with adequate representation by your lawyer (not calling you back at all), you could possibly contact your local United States Trustee's office. But I suspect if you let the lawyer know you want to substitute another lawyer, he or she would respond in a diligent manner.
If you wish to change attorneys, you can certainly do so. You should ask your present lawyer why you have not heard from him. If there is nothing going on and you have not contacted your lawyer, then perhaps there was no need for him to contact you. However, if you have tried to reach him and he has not responded, that is a different story. Consult with one or more new attorneys for a second opinion and make your decision accordingly. It would be best to discuss your intentions with one or more bankruptcy attorneys before taking any action on your own.