Android Factory Reset: My phone shows weird options when I enter recovery mode, and no button selects anything
If you want to factory reset your phone, just go to Settings->Backup and Reset->Factory Reset. You will be asked to confirm. Now, your phone will reboot and wipe data (do a factory reset).

I will assume that your volume buttons work correctly otherwise. If this is a repeated issue, it might be a faulty bootloader in this regard. If you have to reboot to recovery, you can use adb reboot recovery from the terminal with your phone connected in USB debugging mode to your computer. It should succeed, unless you have a corrupted recovery. In that case, you should take your device to a service center.