Is the aforementioned contract concluded over the phone Islamically valid? And does the second seclusion count as a رجعة (resumption of marital relations) after a divorce in which no consummation took place? And are those seclusions permissible?

A Muslim must ask scholars about what they need to know concerning Sharia rulings, especially regarding marriage, as the default rule concerning private parts is prohibition. Marriage has conditions for its validity, the most important of which are the guardian (wali) and witnesses. If the marriage contract is without a guardian or with only one witness, it is invalid by agreement of the four madhhabs (schools of thought), and divorce consequently occurs. If both parties wish to marry, the contract must be renewed correctly. Care must be taken in choosing spouses, and each party should inquire about the other; what is called "getting to know each other" before marriage is an invalid approach.