Translation of endurecer

The entrance hall had a design of the seventies which I found charming. An older man came towards me an asked me whether I needed a ride. I agreed and we drove to downtown of Havana, capital of Cuba.
Sounds great. Sorry, it took me a while to get back to you. Did you book the Helmhaus (which Monica suggested) or the Seidenhof (which I gave her in the end)? Will make sure, they give you good rooms...
The travel agent's representative promised that they would return us the difference of the money. They also assured us that we would get special treatment, such as extra drinks and a Kayak expedition.