Verb conjugation of "crack" in English

The billing of additional working hours is not justified, since it was our request to download the software and wait for the new version. They have admitted the error of the translation.
Could you please read the following offers in a critical manner and confirm it before I will send it? I have also mentioned the warranty and the software in the offer, because it was requested by the customer.
Great that you've written me back so quickly. I want to be your pen pal and we could help each other. I am looking for people who could help me learn Spanish, with focus on conversations.