I was told by the lady I spoke to when I applied for my daughters upgrade that they will call off a withheld number 🤦♀️ Have you tried resending your email again? It seems to be pot luck when they answer, but don’t loose hope some people have been getting a call the day before they go away to collect there passport. Keep chasing them through the main number and try emailing again. You would definitely be eligible if you are going away so soon and it’s for a renewal. Good luck 🤞