I hired an Engineer to pull permit for a mobile home. He asked for $2,500 down payment. He mentions he believes it will be between that and $3,000 at $100 for him and $60 for his assistant an hours plus .55 per mile. Shortly before the process is done he informs me that it went over and I owe him another $6,000 plus. I paid it. A couple of days before final inspection he tell me there will be additional $600. It passes final inspections. I pay him in cash the last of the money I owe him and was surprised he didn't ask for the additional $600. He gives me all the paperwork associated with the project and that's it. Now 5 months later he calls me and says that I owe him an additional $3,500. For what I don't know. Can he bill me for something 5 months later? Can I ask him to send me an itemized statement of charges which he never has supplied me with?