Could I get some advice about this letter to my lawyer?

The following is what I have written to my lawyer. My case is not difficult, I have 3 years of proof in email form, that all my request for visitation were denied by my ex. I have joint custody, there is no proof against me that I have done anything wrong, illegal or abusive toward my children or my ex. I actually asked my ex to take custody because it was in my children's best interest. I retained this lawyer in May after once again being denied visitation. My ex is in Afghanistan now and my children are 2500 miles away living with their step-mom. My lawyer has only responded to emails after I sent them a second time. The only response was that he spent 17.3 hours on the case and now I owe him more than the $2000 retainer. I haven't even received a case number or seen any documents that he says he filed!

I would like to know if this letter is appropriate & aggressive without being rude!

Letter to lawyer:

I do not know what to do. You are telling me that you spent 17.3 hours on my case. I still have no proof that you have even filed for the modification. I am sorry but I do not believe that a lawyer with your experience and years could take that many hours to file for a simple modification. Also because you have not given me the information I requested nor responded in a timely manner to my email request for that information, I am increasingly concerned that this is a breach of contract on your part.

I do not desire to seek other counsel or to file a grievance. When I hired you in May, I really felt that you cared about my case and that you understood that I am seeking what is in the best interest of my children. I am no longer sure that this is true.

What can we do to resolve this problem?