The problem is that the only people with data are the Credit Card companies and the VPN providers, and they both have dogs in this fight. We wouldn't believe the numbers they released, if they released numbers, which they probably won't...
So we're left with anecdote and personal opinions to base our decisions on. There's plenty of opinion in this thread - a few anecdotes won't hurt.
Chargebacks are bad for the VPN company. They cost $15 each.
Even if they cost nothing, a high ratio of chargebacks is not in the best interest of the credit card companies, who are at the top of the value chain. So chargebacks are bad for anybody along the chain.
So we're left with anecdote and personal opinions to base our decisions on. There's plenty of opinion in this thread - a few anecdotes won't hurt.