Thanks!
I was finally able to link it. I called for an agent, and apparently the problem was that they had another city of birth than what I wrote in the application. The city is the same, it's just that they had a different name registered. Using the name they had automatically gave me a result.
So for those who have problems linking, the information has to match what they have on their system and not necessarily what you wrote exactly, so if you're sure you are entering the correct info, give them a call. Another problem the lady mentioned could happen is if your name is too long and they shortened it, it won't match. Finally, if it's spouse sponsorship, you do have to write 2 people.
Hope it helps somebody