1) you should not sign any blank document
2)send an email to your husband not to use the blank vakaltnama for any purpose
3) mention that name of lawyer was not mentioned and that you have not authorised lawyer to appear on your behalf in any legal proceedings
4) in the event your husband uses said vakaltnama for divorce case issue notice to your lawyer that you do not want him to appear on your behalf and to furnish his NOC to enable you to engage another lawyer
5) appear in court and seek permission to engage another lawyer