1, your behavior belongs to concealing the truth and defrauding a large number of public and private property, which is a kind of fraud.
To refute, it can only be based on illegal possession, and can only objectively emphasize that "for various reasons, the development of B can't be carried out, so you decided to develop it yourself without telling", which belongs to unauthorized agency behavior.
Your opinion is that if you provide equivalent software technology, it can't be counted as fraud. However, if the law uses fraudulent means to make others fall into a wrong understanding and defraud property, even if they pay items of equivalent value, they should be considered as fraud.
The other party can completely start from "he gave you the money based on his technical trust in B", but you concealed the truth and intercepted the money on the grounds of illegal possession. Even if you provided equivalent items, it would constitute fraud. Unless you can prove that A gave you money because you trusted your technology, and that you are an entrusted agent, you used the money for the purpose of obtaining technical software. But you just wrote a note, and the other party has every reason to insist that you have no right to decide who will take whose money and who will do it.
3. The other party thinks that your fraud is not based on the effect and quality of the software. Just because you concealed the truth and illegally possessed money.
4. Responsibility for the crime of fraud: According to the provisions of Articles 151 and 152 of the Criminal Law, cheating a large amount of public or private property constitutes the crime of fraud.
The higher people's courts of all provinces, autonomous regions and municipalities directly under the Central Government may, according to the economic development of the region and considering the social security situation, determine the "large amount" and "huge amount" of personal fraud in the region within the range of "2,000 yuan to 4,000 yuan" and "30,000 yuan to 50,000 yuan" respectively, and investigate the criminal responsibility of the relevant personnel.
Whoever commits the crime of fraud and the amount is relatively large shall be sentenced to fixed-term imprisonment of not more than three years, criminal detention or public surveillance, and shall also or only be fined;
If the amount is huge or there are other serious circumstances, he shall be sentenced to fixed-term imprisonment of not less than three years but not more than ten years and shall also be fined;
If the amount of fraud is less than 30,000 yuan, it shall generally be sentenced to fixed-term imprisonment of not more than three years, criminal detention or public surveillance, and shall also or only be fined. It is impossible to give specific sentencing standards. It can only be said that it is generally within this range, and it depends on whether there are other statutory circumstances that can be lightened, mitigated or exempted, such as minors, blind people and deaf people committing crimes, surrendering themselves, making meritorious service (significant meritorious service), and whether there are other discretionary circumstances.
So what is your tens of thousands, and your belonging is the key to judge the size of your responsibility.