Furious

I really wanted an arch like the one pictured below. Our florist told me her husband was going to build one for us because she didn't have any like this. Instead without telling us, she purchased one online along with a bunch of different types and colors of linens. Mind you we only would need white linens. She wants to charge us the entire cost of the arch and linens. It was approximately $500 for the arch. Not sure how much she spent on all of the linens she purchased, but told me she was going to charge us $800 for the arch and linens. She already gave us a quote for the rest of the decor and $800 would take us over budget. She claims we will be the only ones to ever use it as she does mostly rustic style weddings. I feel we shouldn't be responsible to pay for the entire cost of all of the linens and arch because she purchased it without asking and there is no reason she can't reuse it for other weddings. I am so mad because this isn't the first time she has misled us. She told us signs were included in the cost she quoted us, but she failed to mention that the signs she was talking about were chalkboards and we specifically told her we didn't want chalkboard signs. Do you think we should be responsible for the entire $800?