Does anyone have an average percentage for hotel rate increases?

I'm livid because I booked an extensive trip with a reputed agency 10 months ago. They have done very little in the 10 months since contracting them. I sent them dates and specifics, along with a 25% deposit, which they retained. I've been fighing tooth and nail for details, final number, etc for the past 10 months. They finally just got back to me with the figures and it's a whopping 25% increase over their initial quote, which is no small change! We're talking a difference of almost 800,000 yen! I am obviously not going to accept this and find it entirely unprofessional that they did not even offer a price breakdown; simply a plain blank spreadsheet with a sum figure, signed and dated. If it were 5% I would not have said a word; 10% and I might have protested (at the very least inquired as to the breakdown of charges) but 25% to me in absolutely inexcusable. I have been requesting these numbers for 10 months and in all truth, up until two months ago, this travel agency hadn't lifted a finger - we hadn't a single booking confirmed, despite all my persistent efforts. When they did finally go to work, they completely neglected our dates, rearranged our itinerary, downgraded our rooms, apologized for unavailabilities - basically, made a disaster of the trip that I had been planning for over a year and all of the oversights which could not be excused given the 10 month interval in which I had initially contracted them and sent down payment. So what's the purpose of this thread? I would like to know if anyone has experience with annual rate increases on properties (on average) in Japan - notably Tokyo, Hakone, Nagano, Kyoto, Osaka, Nagano, etc. I understand it's impossible to come up with an exact figure, but as there's zero correspondence between the initial quote that was delivered to me 10 months ago and the final cost received just this afternoon, I'd appreciate some context on this matter.

Thank you.