Using a credit card causes people to spend more than their budget because of high fees, interest, hard to be cancelled, and dealing with numbers.
You have to pay flat monthly fees for every credit card. This flat fee covers a number of your transactions, but you still have to pay for every transaction over what the flat fee covers. Using the machine of another bank will cost you in paying more fees. Some stores charge you for using a credit card even if you do have a good monthly fee to cover your transactions. The monthly flat fee doesn't cover using any other machine. When you get your statement at the end of the month you will find out that the fees are more than what you think.
There is a high percentage of interest if you don't pay the full amount before its due date such as 18%.
By paying only the minimum amount every month you will never be able to pay it all because the minimum amount is the interest.
If you sign up for something such as newspaper using your credit card it's not easy to cancel it. When the sales person sells a newspaper with a credit card he/she gets tribal the commotion of a sale with the other methods including cash.
When you go to buy any thing from a store, or internet, or phone you only deal with numbers. You don't touch the money, or count it, or see it. Those things makes it easier to spend more than what you plan to spend. It's not easy to find out how much you have spent in the middle of the month because you didn't touch the money, or count it. Small mistakes in entering the purchase total could cost you...