4 mnths of waiting for a letter

I have requested the firm to assist with handling my aunts deceased estate. I was initially working with a lady called Lucinda > She was handling the file and after all papers were submitted i waited and waited for a response. I called in a month later to find that Lucinda had left the firm and the file was handed over to Naima. Then the drag began. I would call leave lots of messages but this lady would not respond. When i complained to one of the attorney's about here she then called me back and advised that the power of attorney letter will be issued in 2 weeks. I have since been calling in for feedback, i would be lucky if she took my call. Two weeks has now become 4 months, I am not sure what to do now. My nephews had to change schools now due to finances and the funny thing is if we had this letter all would be taken care of. I am not happy with the service i have received . IO am not sure what to do now