The last time we stayed at the Lagunamar in Cancun, we used a woman by the name of Martha Cameron, who has a website grocery and delivers to your hotel. Find her at
cbdwedeliver@gmail.com She was great!! The cab cost alone to and from the big grocery store would be around $40 plus tips and you have to shlep the groceries and heavy water bottles yourselves not to mention the time savings.
We're going back next year and will use her again. The only thing is, you have to pay in advance. I used pay-pal but she uses other payment methods as well. Our groceries arrived the day we checked-in and the bellman delivered to our door. The service charge was well worth it.