Please proof read this letter

A while back, my mom signed me up for some vocabulary memorizing service which I have since found to be very unsatisfactory (considering we paid 900+ US dollars for it). I'm sending them an email to ask for a refund, and I'd like to make this email as powerful as possible which is why I'd be eternally grateful (900 dollars worth anyways) if someone can help proof read this letter and tell me which parts need improving:




Of the amount of time that I have actually spent using mintel, it would about 15 minutes a day for a quarter of an year. Right now, I am very unsatisfied with what I have recieved out of this program. I bring about two very big points to justify myself. First, most of your definitions are either horribly incorrect, or defined with words that are at a much higher level than that word itself, or have an example that does not match with the definition. I constantly have to look in the dictionary for these words due to these impedences. Along with a slew of english errors in your definitions, every now and then you'll have a careless software error. Some words have examples that will not fit in the box, and some words lack a definition. I have compiled a list containing a small fraction of the words that are incorrect in one way of another and it is already quite long. I can, if you would like, type up and send you part of this list. The second point I bring about, mintel says that it uses a "powerful memory engine". I did find that I remembered most of the words at first, and very well indeed, but as I finished TOEFL and started on GRE, I started to notice that I was no longer able to remember the words quite as well. Now, after having finished GRE, I can no longer remember the words at all! When I start SAT plus, I find myself struggling to stay awake and to focus, and I often find myself autonomously clicking the green circle wether I know the word or not. I have noticed myself, and I'm sure I have done so without noticing, skipping many words that I do not know. I do admit that there is a list of "known" words, however this list only shows a 20 words per page, and is not even alphabatized. SAT plus contains 5000 words, and I know a better 3/5th of them, that means that if I wanted to find a word that I accidentally skipped, I would have to look over 3000/20 = 150 pages of words. These two problems are perhaps the most obvious that your service has, but they are not the only ones, I am constantly finding new errors in your system and am quite displeased by it especially having paid 900 dollars. I have provided sufficient evidence that you do not provide what you promise, and what you promised was, by itself, rather unreasonable for 900 dollars, which is why I am asking for a refund.
Thank you.




thanks in advance, will proof read your paper in your time of need if you proof read mine ^__^.