Yeah pre-paid credit cards are the way to go if you can't get a real one. Stop by your local 7/11 (some others might have them) or grocery store. There will be a fee for purchasing the card and it will cost some to put the money on paypal but all in all its still possible.
There still is a paybyphone option but it doesn't work many players attempt to use it only to find out they don't get their membership so I won't explain how to find it or how to use it.