Getting out of a paid-off time share

A couple of posters have touched on a similar issue, but I would like to see if anyone has words of wisdom for my situation. My husband and I bought a week at Hacienda del Mar in Los Cabos in 1995. This included a membership with RCI. We went to the resort twice, and gifted the week to children for their honeymoons a couple of times. The rest of the years, we exchanged with RCI and went elsewhere. We never saw this as an investment, and never felt scammed, even though I realize it may not be the best value. We cook, my husband doesn't like to eat out, so for years having a small apartment rather than a hotel worked for us. For the past 3 years, Hacienda del Mar has not replied to my emails (to deposit my week) and we also have not been able to go to Mexico. So I have paid the maintenance fees and RCI membership for nothing. This is getting old. Fees were $375 in 1995, but are now almost $1,000 and go up every year. There are only about 7 years left on my contract. While we are retired and have more time, I no longer drive and getting away is not as easy as it used to be. The service offered by RCI has also declined, as has the number of available resorts. They introduced a system of relative value for properties that severely limits choices and there now are daily resort fees in addition to everything else. So I just want to dump the time share. I am aware that I won't be able to sell it and that companies that offer help are just as scammy as the time share companies themselves. The unit was paid for long ago. Concord Servicing is the company I pay my yearly maintenance fees to. They're in Scottsdale, but I suspect they only collect money. And make your life a misery if you just stop paying the fees, I'm sure. The time share company is Quinta del Golfo de Cortez, and they're in Mexico. Whom do I contact? I just want to give it back and have nothing more to do with it.