There are many ways in which you can let a friend use your credit card. You can either simply hand over the card to him, make him an authorized user on your credit card account or make him a joint account holder. Either of these scenarios should be considered carefully and after much thought as you risk potential damage to your credit score and credit report in case your friend charges your credit card but does not pay as agreed. Since you are the primary account holder as well you are liable for any debt that he runs up on your credit card in spite of whatever understanding you might have had with him about the repayment. Whether he is a joint account holder or whether you just gave him your card for use on a personal understanding you will need to make the payment of the debt in case he does not to avoid damage to your credit score and negative information of non-payment being reported to the credit bureau.
As for the legal recourse that is available to you you should consult an attorney as to your rights under the situation. In case your friend has used the credit card to make purchases and has refused to make the payment as earlier agreed you might have the option of sewing him in the court recover the money or repossess the items that he chased using your credit card. On the illegal professional can best advise you if you have any authority to claim money or the goods you find a chased using your credit card.