DON’T DO ANY FINANCIAL STUFF ON YOUR PHONE!!!! SIM swaps aren’t the only way they can hack you. Ignoring this principle is just stupid.
For that matter, don’t do any financial stuff using ANY form of online communication, except credit card transactions which are revokable. Don’t use Paypal. either.
Never use the cell phone for anything but phone calls and occasional test messaging. Very rarely use it - it’s really only for emergencies.
However, I’m going to review the paypal statement and try to find some other way to pay for stuff on ebay.