I can't believe I am reading this. You ordered NEW FURNITURE for a guest??
First, I always caution against long term guests because they can be problematic. Bad match and its not a few days of dealing with personality issues-- its a month or two. Plus Airbnb does not guarantee paymet beyond the first 15 days so you better hope your guest is honest. But this is so far beyond the pale I have a hard time believing its true.
You are doing your fellow hosts a disservice by undermining the terms of a booking. In a booking your job is to show your space accurately and your guest's job is to select the space which matches their criteria. If a guet fails to do their job and says "you know, I prefer different furnishings" there is no ground to accommodate that because you provided exactly what you showed the guest you would. If you then GO OUT AND BUY A DINING TABLE despite the tacit agreement that there was none when the guest booked, you have given the guest free reign to break all the other pieces of the agreement any time they feel like your place doesn't match their Airbnb fantasy. Once a guest has this in their head, what kind of expectation will they have of hosts who follow the regular old rules and don't provide them with a new king bed, hot tub or renovate the bathrooms to their standards during their stay? I mean, where does it end?
Just stop now. I would say this to your guests:
"I am sorry that I gave you the impression that I would make changes to the space based on your preferences. I was trying to be a good host and went overboard. I can't provide any additional items, furnishings or amenities beyond what is stated in the listing. I know you will have a comfortable and enjoyable remainder of your stay. Please let me know if you have additional questions about the space or how to use any of the items provided. I cannot reimburse any purchases beyond what we have already agreed. I am sure you understand. Have a great day!"
And then that's it. No more glasses or tables. Refer to house rules. Answer questions promptly and politely but for the love of all that's holy, put up some boundaries. If not for yourself and your own aggravation level, for the rest of us. Because if I get this guest, there is no way I am spending $1000 to retrofit my space to their decor preferences and they should not have the expectation that anyone would.