Aeromexico review: Wrong airplane gate information

Reservation # IWMTTG: On 10/22, we arrived to CDMX from Puerto Vallarte with plenty of time to catch AM 2970 to Nuevo Laredo. Upon arrival, we were told it would depart from gate D. We checked boards constantly and paid attention to announcements. Nothing was ever said nor did the flight appear on tge board. When it got closer to time, my wife went to ask a gate agent and was told it had changed to K just as they mentioned it over the intercom. We ran over there from D, but by the time we arrived, no one was there. We asked customer service desk and they said gate had closed and proceeded to argue with us that the gate change had been announced and that they even called us by names (all lies) and that it was on all boards (not at D or E sections). The one time they announced the gate change, we went to it. As we were arguing, another group arrived and said the exact same thing we did, that they were also told to go to D and the gate change was never announced nor were their names mentioned. It wasn't until the same announcement we heard (there were 4 of us in our group). So once that other group arrived and said the same, customer service reps softened up some and helped us. Unfortunately the next flight would have been 10/23 and we needed to get back 10/22 (same situation as other group). Solution was to fly to Monterrey and get bus, which addes another 8-9 hrs to our trip plus extra expense for 4 tickets.