Legal advice: in this case, need ev

Legal advice: in this case, need evidence of money in advance 5000 Bill pay to Tom. The lawyer asks for proof that Tom will sell his business, 50000, However, there was no receding or proof of such an agreement being made. This case is considered the breach of contract. But will need support with concrete evidence.
The bill must get the receipt from the Tom or Tom to write a bill evidence to get 5 000, and then pay the rest 45000 buy business.