We need guarantees from PrePly, which have not yet been met

For students:
Must require a contract agreement in any format from PrePly, even though they are in another country. The document must must be signed by both parties. This will give you a legal basis for a refund.

For faculty:
Must be executed a contract-agreement on cooperation between the private tutor (teacher) and PrePly. This document should be signed by both parties and on it must have the seal of the organization and its details.
Teachers are required to undergo verification, which teachers do. But their PrePly data prefers not to give it away. This is not decent. There is no formal assurance (in the document) about the personal data received and stored. Only an anonymous sign on the site that the data will be deleted after verification.