Credit cards common issues

I paid my bill on time last month and still was charged a late fee. How can that be?

Why did I get a low credit limit on a credit card?

I just received a new card from the card issuer with a new account number and a letter saying my account had been "compromised." What does that mean? What should I do?

I just learned that my card issuer has closed my account without giving me any notice. Can they do that? What can I do?

I did not receive a bill last month. The current bill shows a past due amount and charges interest for the charges from the prior month. What should I do?

I agreed to allow my card issuer to charge an overlimit fee if I exceed my credit limit. I needed to make a purchase that would have put me over my credit limit and was prepared to pay the overlimit fee, but the card issuer refused to authorize the charge. Can they do that?

My new credit card won't work. What should I do?

My children are under 21 years old, but they receive invitations to apply for credit cards. How is this possible?

My spouse and I had a joint account. We are no longer living together and the monthly bills have been sent to my spouse’s address. He/she has not paid them and now the card issuer is charging late fees. Am I responsible?

I sent my payment to the card issuer but I: forgot to include the payment stub; sent the payment to the wrong address; sent cash rather than a check; sent a check in foreign currency. What happens?