swap the servo connectors at the receiver.
If the right aileron still doesn't work, the servo is broken or the linkage is glued/stuck.
If the right aileron works and the left aileron is now bad, the transmitter-receiver is suspect.
Replace the receiver, put it all together, test it again, If the same issue remains, the transmitter is defective.
Did you resolve your balance charger issue in your other thread?