Anderson Drapery

My father recently needed to replace pinch pleat drapery for 2 sets of full length casement windows and one sliding patio door. We used existing rods and rings.
My father is elderly and disabled, so my sister and I worked with him to help get comparable estimates and get the replacement scheduled. After receiving several estimates, we decided to go with Anderson Drapery, even though they were more expensive, because they did the original drapery years ago and they were high quality and held up well. Both my sister and I live out of town (I’m 1000 miles away), so we were not present for the installation, which occurred in late February. When I arrived a week ago (Mid April) to see the result, I was dismayed to discover they kept the original 45+ year old cording, which is starting to fray and, in one case, is frayed down to the core and about to snap. After speaking with my father, my understanding is that this was not included in the original estimate, but he had no idea that cords should have been included. Therefore, I went down to the store to talk to the management and find out what our options were to get this rectified, as it is very clear that these cords are going to snap in the near future.
When I went to the store, an older woman greeted me, and I told her that I wanted to talk to someone about the recent job done at my father’s house. I explained that my father had recently hired Anderson to replace 3 sets of drapery, at a cost of ~$ 2600, but the cording was not replaced. She immediately became defensive, and firmly insisted that re-​cording was not included in the quote. I told her that I understand it may not have been included, but I wanted to understand WHY it wasn’t as it is pretty obvious they need replacing, and what at this point can be done about it. She told me that my father did not ask for it, so they did not do it. I pointed out that my father didn’t *know* to ask for it. As consumers, we get quotes from experts, who should inform us on what is needed. THEY are the drapery experts, therefore one would expect the expert to provide a quote with all of the items required for the drapery replacement, including the ability to open and close them. If my father refused to include something that was recommended, then we need to pay the consequences, however he was not given an option to replace the cording, which apparently is now a very costly job when done after the fact (I am not exactly sure, because Anderson would not give me a price for it — she just told me it was big deal and would require all of the drapery coming back down, rods sent into the shop, and then re-​installation). She then became extremely belligerent, telling me that my father wasn’t the customer — that an insurance company was. I showed her the receipt that clearly listed my father as the paying customer, complete with the check numbers he wrote to make payment. She continued to be extremely uncooperative. At this point, I told her how disappointed I was with their willingness to try to figure something out and that I planned to write a review of my experience. She then started literally screaming at me and (no kidding) threatened to sue me if I posted a negative review of their business. Maybe I hit them on a bad day, but I have never experienced such a complete lack of respect for a customer. The drapery looks well made, but the fact remains that my father paid a very high price to end up with drapery that he will not be able to open or close.