The fans are useless unless it's actually lowering the temp, like if the air outside is cool and the fan is pulling it into the room. Chins don't/can't sweat, so unless you are pulling cool air in all you are doing is blowing warm air around. Air flow helps it not be stuffy, but doesn't help to cool them like it does us. Also a fan blowing on the chins can actually make them sick, so make sure the fans aren't blowing on the cage.
Unfortunately there really is no real replacement for AC, is buying a new AC out of the question? Even a cheap window unit is better then nothing (and is cheaper then an emergency vet visit, or the emotional cost of losing a pet do to something preventable). Or is there a cooler part of the house you can move them too, like a basement? Or do you have any friends or relatives that have AC that can take them to until the AC is fixed? Or possibly book a room at a pet friendly hotel that has AC until the AC is fixed or the temp cools? You could also try calling vet offices and see if they can board your chins until the AC is fixed. Ice packs are only a very temporary fix, and you have to make sure you change them out every half hour or so depending on the ice packs until the temp is below 75 again. You'll need to have enough to last until the AC is fixed, so maybe 12-48 per chin for a day worth of them depending on your freezer and the ice packs so you always have frozen ones to replace the thawed ones. Also you need to make sure they are covered so the chins don't get wet or eat the ice packs, and you will need to keep an eye on them to make sure they don't try to chew the covers off too. However, ice packs or frozen water bottles only help if the chin is willing to stay on or near them, not all chins will. You can also use frozen tiles and stone slabs (dried off so the chin doesn't get wet), but once again it only works if the chins will sit on them, and they too need to be changed out as they warm. Most of the other options I know of are really temporary quick fixes, like putting the chins in the freezer or fridge with the door open (so they don't suffocate), drive around with them in the car with the AC on, stuff like that. If they start showing signs of overheating you need to get them cooled immediately, and get them to the vet.
The other thing an AC unit does is pulls moisture out of the air to lower the humidity, so you need to watch that too, if the humidity gets above 50% the chins can also start having issues. So without an AC if the humidity is also high you need to get a dehumidifier as well.