Is it permissible to take the data of customers who reject the company's high prices and contact them to offer the same services at lower prices outside the scope of the company, and would this be considered a breach of trust?

The customer and visitor database is specific to the company, and its access by external parties could compromise its interests. Therefore, trustworthiness, in the custom of merchants and companies, dictates that these data should not be exploited for the benefit of anyone other than the company. The employee is entrusted with the data of their company's customers, and their salary is for promoting its products, not for promoting competing companies. "And let him come to people as he would love to be come to." Your view that the company's prices are high does not justify that; because the owners of wealth are more knowledgeable about the prices of their products, and the Lawgiver (Islamic law) has not limited profit to a specific margin.