Gifting and help centre help please

Hi, I am having a couple of different issues. My son requested to purchase Nugs on a game from his child account, I approved it and tried to purchase it on my parent account, the first time it let me purchase and gift them but they didn't go through to my son's account, I tried again and now it is saying unable to gift. My second issue is I tried to access the help centre from my horizon account but it is saying that I dont have a device associated with the account and when I put the serial number or my email address in it is saying not recognised so I can't use the live chat feature. Has anyone had any of these issues before that might know what I can do to fix them please?