lol 2nd round and it ain't complete? I would suggest that you withhold payment until all is complete. For me, my payment terms was that I paid 50% upfront and then I paid the rest of the 50% a WEEK after it was completed to make sure everything was ok. Rather than the LFS asking me for payment, they told me to WAIT until everything is confirm ok then pay them. THat's the way to go in a service industry.
I feel that if time management and resources is not being managed properly by your vendor, it's not your problem. It's up to the vendor to prioritise and plan. AS a customer, we have all the right to demand for things done right. Yes a level of error can be endured but not when multiple trips have to be done. Your time is also precious, your money is also precious. And if you have to keep on waiting and waiting and things aren't delivered right, that's wrong too. AS a business person, be professional and don't give excuses of why late la, wrong la etc. That's not a customer's problem. We can be understanding but up to a certain point that we do not need to hear about don't know what story, dio bo?
Hope that your whole setup will be done up right by the 3rd visit. Your setup looks very simple. I don't see why so many trips are needed. Kudos to you.