Your question raises a number of further questions making any definitive response impossible. You probably want to consult with an attorney experienced in credit. Fraud requires a conscious knowledge of the fraudulent activity. If you acted under the belief that you had a right to use the card and did nothing deceptive, there is a good probability that fraud does not apply. To the contrary, if your boss/friend advised you to stop using the card and return it, and you ignored the request and kept using it, there could be legal issues.
I recommend that you contact an attorney with whom you can discuss the matter in detail to obtain an evaluation of the circumstances.
This response is for informational purposes only. It does not create a legal engagement between questioner and answerer nor does it create an attorney client relationship. The questioner should retain an attorney for legal advice.
There are too many facts missing to give you a good answer. What was the reason you were given the credit card? Etc., Etc. Was any limit discussed? Etc., Etc. If the interest charges are more than $200. per month, you must have charged over $10,000. and have balance of over $10,000. . As Long as you keep paying off the debt the DA probably would not want to bring charges. SUGGESTION: Pay a lawyer a consultation fee and discuss the matter with him or her in more detail.