"60 is sixty regardless as to when you turn 60." If being 60 at the time of registration is, in fact, the requirement as opposed to having turned 60 by some cutoff date.
I have seen that error reported if the CURP was not entered exactly correctly. Probably not the issue, but ...
Locating and verifying your CURP.
It doesn't seem to like my CURP or thinks I'm not 60+. What should I do?
The number is on your Mexican Driver's License and Permanent or Temporary Resident Card. At least it is on mine.
Make sure you entered the CURP correctly including getting Ohs and Zeros right ('O' versus '0'; letter versus number) right. One way to do that is to copy and paste it from someplace else where it is correct. Letters versus numbers is only an issue for the last two digits of the CURP which can be either numbers or letters. The web site currently validates that the other positions are of the right type (numbers versus letters). Still, copy and paste is a good way to make sure the whole thing is right.
To get a good version to copy-and-paste from and to locate and verify that you have the right CURP (and that it is in the system), try going to the
Check Your Curp site. You can type in your CURP or find it by using your Personal Data (name, date of birth, etc). See
Locating and Printing Your Mexican CURP, including the comments, for instructions.
Once you do that and have verified that your CURP is correct, try using that (copy-n-paste for best results). If that still gives you an error
about your CURP then I think it is an error in the system and, for now, I would hope the error gets fixed and I would try again tomorrow. (This may be a new error recently introduced into the system.)
From:
How to register for the Covid Vaccine in Mexico - Now Open for 60+ year olds
And, no, I am aware of any phone number (yet) or place to correct this.
But, see:
Vaccine Roll-Out Interview for San Miguel de Allende (Direct link to interview google document)