Hi and welcome!
If my little search turned up the right stuff, renew bariatrics is a medical tourism company. You don't need them, they are just a middle man, so to speak, that will line you up with one of the surgeons they contract with in Mexico. Not necessarily the best surgeon for you, and I'm not saying a bad surgeon, but not hand picked for you.
There is no good reason to go through them. You can easily arrange your own surgery in Mexico, if that's the route you are going. Around here, we recommend Dr. Esquerra in Mexicali. His office staff will assist you with all arrangements, and there is no additional fee for this. And while you're at it, I hope you will continue your research and look closely at all your surgical options. Sleeve isn't a bad operation, but you have already (apparently) not had good results with one purely restrictive operation, do you really want to try another purely restrictive operation? Better than lap band for sure, but still nothing but restriction, which doesn't last forever. There is a lot of good info here about the DS, and I hope you'll read all of it and consider this option. If you still want the sleeve, I would still recommend Dr. Esquerra or his colleague, Dr. Wilhelmy. Just don't waste your money on one of these tourism companies. There is absolutely no benefit to you, and you will do better by choosing your surgeon yourself.