How RUDE is this??

Ok! So last night Alex took Amanda and I to dinner (not physically but he paid so anyways....) we went to The Hydra and it was all a nightmare. First the waitress put us in a table like right in the middle of the walk way.... it was the dumbest place for a table. So Alex politely asked for a booth instead, so she moved us. And she asked if we wanted anything to drink, we all ordered lemonade and I would say like 20 minutes later our drinks showed up. We ordered an appetizer, and 15-20 minutes later we got that. We knew what we wanted to order by then but she dropped off the appetizer and like walked away before asking if we were ready to order.... so then like 20-25 MORE minutes later she comes back and gets our orders... our soup got there fast but I sware it took like 30 minutes to get our food. And she didn't check on us or anything! And we finally got our food and she came back and alex ordered another drink with took forever to get and we were sitting right next to the pop machine! So we asked in advance about dessert and she told us what there was and then left and came back like 20 minutes later!! I mean we asked about dessert... that should have let her know that we were going to order some!! So we asked for dessert TO GO cause we had already been there close to 2 hours. So we got the dessert and the check and alex gave her his card. And when she brought it back is was like 67.? and so he made it an even 70.00 and gave her like a 2 dollar and something tip (she didn't deserve one at all! The place was almost empty and they were over staffed) so we left it there and walked out the door.... and then we hear this "Excuse Me!" and I was thinking, are you kidding me... so we turn around and she's standing outside the door holding up the receipt! She wanted to know if it was a 'mistake' that we left such a small tip! She was like did you have a problem with the service? And Alex and said yeah, it took a really long time. And Amanda said you didn't even check on us enough so we had to wait for forever. And she started complaining saying something like they have to pay %8 of the tip to the hydra or something like that. I wasn't really listening I was just staring at her wondering if she was seriously standing there trying to get more money from us! Who DOES that?? That is SO rude!! And we could see her talking and stuff so she wasn't busy with other tables. Ugh. I just think thats totally not ok, a tip is NOT something that you HAVE to pay. Alex and I always pay %20. ALWAYS. But she was really not getting that much from us. The only thing you HAVE to pay in the bill. The tip is your choice. Its not our problem that she was a terrible waitress!! So i'm calling today and complaining. So what do you guys think? Was she right to do that? SHOULD we have given her more?