So, I transferred an item yesterday, and so today I tried to transfer again, but Steven told my to talk to him tomorrow. Why won't he let me transfer an item, I have already waited until Tomorrow. Please help.
Regardless of this the simple solution to fixing your problem is to Wait another day.
If you wan't to know how this happened it could be that you asked to transfer another Pokemon/ Item before 24 hours of when you transferred the last.