I have Carrier 24000btu Spilt units in my motel. They have remote controls to turn on or off, control temp and so on. They work great but every now and them some stup checks in and starts pressing buttons like crazy and the units freeze up and quit working. I then have to turn off the breaker and reset the unit.
Is there any where I can get a simple remote with only ON, OFF and Temp Control?
Or any other ideas out there?

No universal remote for that system your stuck with that style remote for that system. You can set the remote to sense air temp at the wall unit and not the remote and then hide the remote or just tell them hands off. I personally would go with the hands off.

I'm assuming they are infrared.

Possibilities:
1) Take apart the remote and use paint on the contacts to render the undesired buttons inoperable.
2) Use a learning TV remote and program cha up/ch dn and on off to activate the AC.
3) Have somebody re-package the remote's guts into another case with say a membrane switch. Example: Membrane Switch - Nameplates, Membrane, Switches, Rapid Prototype. It's possible that the modification could be non destructive to the original remote. These http://www.e-switch.com/pdf/TL3302.pdf are probably too small for individual switches. They are available in small quantities from Digi-Key Corporation - USA Home Page.

How many remotes are you talking about?

Yes it is infrared. It is a total of 15 remotes.
I kind of like the paint on the contacts idea.

Might try it tomorrow morning.