Email: You fail to understand that the LDS church believes in prophets today, just like the Bible says that the true church is supposed to have.
Response: The Bible says that there aren't any more prophets. Luke 16:16 says that the Law and Prophets were until John the Baptist. The Old Testament was broken up into two sections: the Law (Genesis through Deuteronomy) and the Prophets (all the other OT books). It is the "Prophets" section of the OT that Jesus was referring to in Luke 16:16. Now we have three options to look at.
First, this can mean that the "dispensation" of prophets was until John the Baptist. Second, it can mean that OT Scripture written by prophets was until John the Baptist. In other words, it would mean that there is no more Scripture written by Prophets. Third, it could mean that the OT Prophets section of Scripture is no longer valid. But, this last option cannot be true.
In Mormonism, either of the first two options is a problem because in Mormonism, Joseph Smith is supposed to be a prophet who wrote new scripture. Therefore, either way, Mormonism's claim of having prophets and additional scripture is invalidated by Jesus' own words.
The truth is that God gave us Prophets (Old Testament) and Apostles (New Testament) for the establishing of the church. Prophets pointed ahead to Jesus. Apostles point back to Jesus. But, now God speaks to us through His Son.
"God, after He spoke long ago to the fathers in the prophets in many portions and in many ways, 2 in these last days has spoken to us in His Son, whom He appointed heir of all things, through whom also He made the world," (Heb. 1:1-2).