OK I have an Arcanist who wants to become a
summoner.
My Arcanist is now level 39 and my Thurmaturge is Level 16
So I went according to these instructions:

In order to become a Summoner, characters must have a level 30 Arcanist and a level 15 Thaumaturge.

Once you have met the class level requirements, go to the Arcanist's Guild in Limsa Limsona and complete the level 30 Arcanist class quest. After that quest is complete the quest to become a Summoner will unlock which will grant you the Summoner's Soul Crystal which you equip

However at the Arcanists guild in Limsa nobody gives me a level 30 Arcanist class quest. Maybe I already done it but even so, how come did I not unlock anything or was told anything?

What do I do?