This is due to cases where someone buys bitcoins with Pay Pal, and then reverses their half of the transaction. Bitcoin payments are easier to make than debit or credit card purchases, and can be received without a merchant account.
Payments are made from a wallet application, either on your computer or smartphone, by entering the recipient's address, the payment amount, and pressing send.
You should never expect to get rich with Bitcoin or any emerging technology.
It is always important to be wary of anything that sounds too good to be true or disobeys basic economic rules.
While developers are improving the software, they can't force a change in the Bitcoin protocol because all users are free to choose what software and version they use.
While Bitcoin remains a relatively new phenomenon, it is growing fast.
Bitcoin can only work correctly with a complete consensus among all users.
Therefore, all users and developers have a strong incentive to protect this consensus.
As of May 2018, the total value of all existing bitcoins exceeded 100 billion US dollars, with millions of dollars worth of bitcoins exchanged daily.
While it may be possible to find individuals who wish to sell bitcoins in exchange for a credit card or Pay Pal payment, most exchanges do not allow funding via these payment methods.