Oddly enough I don't keep a record of every single time I ever log into any website.
Not exact date, but approximately.
I wouldn't be able to tell you even if I could get access to my account because PP helpfully expunged all visitation records a while back when they updated their website and refused to keep old visit records for posterity.
If you can't even remember when you have last visited a lounge, then maybe that's why your record had been deleted. If you last visited a lounge say in the last 18 months, then you may say it's weird for them to delete your account; but if you can't remember when you last logged in and visited a lounge because you actually haven't visited a lounge for 5 years, then it would be normal expectation for the account to have been deleted.
Actually, if you haven't visited a lounge for years, remember how Citi switched our cards from Visa to Mastercard, so we had to register with PP again? Did you do that?
Did you miss the bit about it being an international number in Hong Kong? Not a VOIP number either. Most Australian phone plans do not include international phone numbers funnily enough.
I thought most plans include free calls to major countries? I use Boost and they include free international calls. A few years ago, I tested Optus and Vodafone networks to see if they were good enough for me to leave Boost (which they were not), by using Lebara and Coles, and both include international calls for free. So I just expect international calls for free now.
Anyway, if you can't even remember when you last visited a lounge, then you probably haven't visited for years, and you may not even have registered during the Visa to MC conversion. Just register a new one.
By the way, I recommend using a password manager for these things. A password manager can set expiry dates for passwords, so it's a reminder to log in say once every 12 months, for example.