Sorry about your experience.
We actually were there in June and the best advice I can give is to rent a car. It is not that expensive, parking is free pretty much everywhere, and you can pick up and go anytime you want. Roads are great.
Silly me, I did not make any appointments and just winged it. We had to days to do site visits. The first place was Iberostar and they could not take us after about 35 minutes waiting at the door. We understood. They asked us to come back the next morning, which we did, but for whatever reason they did not let us in. We went to Gran Bahia as well and even though we did not have an appointment, they took us in with no problem. We also had to wait forever at the gate. Security has to locate the WC. The WC was really nice. She took us for a tour around the resort and showed us the ceremony locations as well as the reception locations. She showed us all the pictures of flowers, cakes, decorations, etc. She took out the box with sache colors, and answered each and everyone of our questions.
Next we went to Riu and they asked us to come back the next day. Then we called a couple of places from our hotel to see if they could take us in such short notice. Grand Oasis did. Same thing. She showed us the whole place, picture, list of prices, answered questions, etc.
The next day we went to Riu and both the WC and her assistant were there. We almost went for Riu, but then we found out that their disco does not have open bar. You have to pay for all your drinks.
Next we went to Majestic Colonial and did not have an appointment. The WC had some time down and took us in. She was friendly and also took a lot of her time to answer all of our questions.
Although the wait time at the gate is extremely long, we all must understand that the security people are following orders and it is their jobs on the line if they let you in just like that. They must protect the hotel guests.