>>2815678 (OP)
Before I even showed up in Cartagena, the hostel I booked messaged me saying that the nightly rate was a "mistake", and would I mind paying extra when I arrived? The new rate was double the rate I had paid. I gave them the choice of honoring the reservation or cancelling it and refunding my payment, and they chose to honor it.
At the Monteria bus station I was charged 70,000 COP ($21 USD at the time) for the 250 km bus ride to Cartagena. For that price I was expecting a first-class bus, but instead I got directed onto a dilapidated bus with no A/C and no luggage storage that stopped to pick up or drop off passengers about fifty times along the way, driving recklessly fast between stops. No bathroom break for the six hour ride either. The attendant demanded my payment receipt, but I suspected that they'd then try to charge me again when I got off the bus, so I refused to hand the receipt to him even when he tried to grab it out of my hand by force. Everyone else was paying when they stepped off the bus.
Cartagena city center is beautiful, and the Caribbean breeze makes the city a lot more comfortable than you'd expect. The motorcycle taxi driver was honest and friendly, but street touts and hustlers in the tourist districts are very insistent. I even had one grab my arm when I walked past ignoring him. I snapped "NO ME TOQUE" at him, to which he responded with a mocking comment that made the other touts start laughing. Typical caribeno behavior.
I was so disgusted by the humans of Cartagena that I abandoned my five-day hostel reservation three days in and headed on to Gaira (a suburb of Santa Marta).