The owner hired me to do architectural plans for a house she bought - included extensive remodeling and additions. We have a simple contract. We got retainer/deposits in January and commenced work with scans and as-built plans, CAD drawings (using 3D software) and then a series of schematic studies. She brought in an interiors person (actually an IKEA specialist) - even though I had an associate interior designer working on it. Every time we met she had changed her mind on things - which is fine, just made it challenging to satisfy her stated and desired fast pace. After 6 months and several versions, she stopped communicating, then finally stated she had run into another architect and was working with her. I said that was fine but she needed to square up with us - then we could provide all the CAD files and go our separate ways. In early July, I provided an invoice for some $3K worth of services (in addition to the deposit received that covered my time and that of my interiors person and CAD tech) and 4 days later emailed to ask when I might expect payment as I needed to plan finances. Terms per contract are "payable upon presentation of invoice". She wrote back telling she thought it was weird that I wanted to be "paid immediately" after 6 months of no billing. Anyway - communication has been non existing since then, and continued Emails and calls (all polite and professional) have gone unanswered. I ran into her at a function - she said she didn't know who I was (then suddenly remembered) and mentioned she would take care of the bill. I followed up with another Email and - nothing. About 2 weeks ago I sent an Email reminder that our agreement also states a 1.5% per month late fee which I would waive if she paid in 10 days. That passed. So - I need to know my options. We started in January, I billed in July, it's now October... I should mention that she is a retired attorney for the State of CA - so she probably knows what she's doing which is what concerns me. I'd rather not have to resort to Small Claims court, which might be my only option. I did not file a preliminary notice.