DeCaptcha or OCR

I need an API to decaptcha with my C# program. Now I already have an API, it's recognition rate is about 65%. I need a higher than 80% one. The product you hand over to us should be an dll file I could call in my C# program, a library file is also accepted. The problem which We can't solve is part of letters are overlapping. Out company is abundant in cash now. We are looking for long-term cooperation of decaptcha. Further cooperation: It will be better if you can provide a UI for us so that we can update the library myself to improve it's recognition rate. In case the letter patterns changes, thus we can still keep the recognition rate higher than 80%. I upload a part of the captcha in a zip file. You may have seen another post like this which is published by my collegue. After you see this post, if you are interested and able to complete it, message me to clarify any question you have. The same time, you may start doing it and give me the project ASAP, we accept parallel projects. Anyone who finish, we would pay for him. So you don't need to worry others may have taken over this project. More detail: we would download bmp file using HTTP request from file. The C# function you provide me should load the bmp, processed it and return a String as result. Thank you!