[shaman1]

This sounds unexpectedly familiar to the experience of refurbishing my flat. Goal post moving, postponements, delays, pay in advance and job unfinished, etc.

My take is that you were too flexible and the agency took advantage of that to extract as much as possible. Also the payment strategy (per hour) is not in your favour. For these clear projects (same in constructions) it's best to arrange a fixed price. That of course does not solve all problems because they will cut corners and deliver average work but at least you can hold them accountable and refuse further payments until a certain milestone is completed.

Thank you for the detailed article and good luck with your projects.