Hello,
These are two separate errors.
The first, "Do not offer repeatedly" occurs when someone already has a pending friend request from you.
The second, "You are unable to send any more Friend Requests today." occurs when you have sent too many friend requests in a given day, and is done to prevent spammers from bothering people.

In the case of the first, simply have your friend send you the friend request if it is not showing up on his screen, and you should be able to accept it. If neither of you are able to view each other's friend requests, both of you should log out, clear cache, flush DNS, and log back in. Then try again.

In the case of the second, you will simply have to wait tomorrow to try this process, since you have been locked out for spamming.
Thanks, and let us know tomorrow if you continue to have issues!

OK, and to confirm, you have already cleared your cache and flushed your DNS, correct?

What method are you using to add each other as friends?
Have you tried any other methods to add each other as friends?

>>> Perhaps people wouldn't get so frustrated with your support if you didn't copy and paste the same replies onto every forum thread you're getting
I typed that out, actually. I assure you, I am listening and I am not ignoring you. That message was to confirm whether or not you had already done that, as you had not yet confirmed that.

So the reason I asked these questions is to diagnose and troubleshoot your problem. It really does help if you answer the questions that are asked rather than simply ignoring them. I know they can seem asinine, but they are not.
And the reason is because of this: the typing the name out method is known not to work. Please try to click on your friend manually and try to click the add friend *on attached to their character portrait This method is known to work better with fewer bugs.
Regardless, I will forward your problem to the devs to work on. If this method still does not work for you, you will also need to put in a customer support ticket including your screenshots detailing the issues you have had, because there is nothing we can do for you here. At this point, it seems likely that you have probably bugged out the system from repeated requests and it will need to be cleared out by customer support. Regardless of what many people say, "turning it off and back on again" (i.e., clearing cache and flushing your DNS) really does work for a lot of problems. There's a reason it's the number one go to suggestion for 95% of IT support suggestions worldwide.

Here is the link for Customer Support. I have copy-pasted it for your convenience.