Report your card theft or missing to your card issuers as early as possible. Your issuer company will not bear any responsibility if your card is used in between the time you part with it and you report for the same to them. So, be careful to contact your creditors at the earliest and tell them what has happened. They will immediately block your card from further usages.
Now, you generally do not keep your issuer number with you always and you might be away from your home where the toll free of your card issuers can be found when the card is lost or stolen. What to do then? Call your friend or any relative who have cards from the same issuers. Get the numbers from them and call the creditors. Alternatively, you can keep the numbers at your mobile draft box.
When you report your card lost and stolen, ask your issuer to send a new card to you. If your account is current and you meet all other card criterion, you are supposed to get a new card with a new card number within 10-14 business days. The card will have the same account number. However, the PIN for that card will also be changed. Most issuers send PIN to the cardholders automatically. You can also request them for the same. If your account has an authorized user, his/her card has to be sent as well. However, if your account is not current, they will still block the card but you will get the card when you bring account to current status clearing off outstanding balance.
It is also advisable to follow up your lost and stolen report with a letter to them. Send them a letter stating your account number, the date when you saw your plastic last and the date when you report the card lost and stolen. Try to send the letter by a registered mail so that you will get a acknowledgement receipt of the same for your future reference.