Frankly, we've tried to keep rates as low as possible, but over time, we also have found there's a ton of work that needs to be done for some clients who come on board. It really depends on what they do.
I do 2 things for clients: 1) provide them rankings, but 2) and most importantly, what the rankings translates into traffic. I dive into the google analytics. Do those rankings equate to improvements in traffic? Do they help you evaluate your google analytics to show you that they do?
Rankings are not the whole picture.
Also, for some clients who do want to know more details, I provide details of the sources I pointed out above (OSE, Majestic & Google Webmasters). I will tell them how their links have increased or rather prove it via those sources. So, I'll give whatever a client basically wants within reason. These have given us very positive ratings everywhere clients have rated us and happy clients as far as I can tell. And for now, I think these are the main reports that show that we "did something" frankly.
Sorry, but when I reread this, this sort of sounds like we're selling our services, but frankly, all the above is what we do because we feel like it's fair communication. An SEO or an SEO firm has an obligation to report their work as much as the client wants to know...and I'm sorry, but it sounds like you haven't had other standards to compare it to in the past. Thus, the feeling of not getting what you pay for.
By the way, have you asked the provider these questions? If not, definitely do.