Grand Mammoth Resorts is now Grand Welcome Mammoth at 587 Old Mammoth Road #2, Mammoth Lakes, California.

Property was ok, the customer service is non-existent. This company needs to be stopped. After reading through other reviews I now realize I'm not the first person to get ripped off by these people.
Here's the story.
We booked a condo through a third party for four nights. The best day we realized we needed to shorten our trip by one day at the tail end. We also never got a confirmation email from GMR. I emailed them asking for the confirmation of stay and to ask if we could shorten our reservation without penalty. I never got a response. I then called them to make the same 2 requests. The lady told me we could shorten our reservation by a day without a problem and hat she would send an email that afternoon. I never got it. When I showed up for our reservation I asked them if we indeed could shorten our stay and they said it was all taken care of and gave us access to our condo. Upon leaving (a day earlier than originally planned but supposedly changed by the company) I called the office to check if we were all set to leave and she told me yes. When we got home, we noticed that we were indeed charged in full, including the day we supposedly asked to be removed. When I called the office, the women told me she had no record of a change, any phone call, email and she could not help me. She told me to contact the third party I originally booked with as they were the ones that would have had to make the reservation change. However when I called the third party they informed that they had no access to GMR system and they never change reservations after they're made. I have since called GMR 5 more times in an effort to resolve this with their manager but somehow he is always gone and has never returned a single phone call. In addition to this, here's how shady they are. I had to call them from a blocked number otherwise they would not answer my calls! DO NOT GIVE THESE PEOPLE ANOTHER PENNY!