Proof of services rendered

[powerbreaker]

I own a service based business where tangibles are not sold. I have a customer that is disputing charges totaling $1050.
I charged the customer's card through a virtual terminal but the employee may not have completed the credit card slip when he met with the customer. If no slip is available, am I out $1050 or is there some other proof that I can provide for services rendered? This was an American Express card used.

Thank you.

[sahilmiddha]

i m not sure about this , but there must be any way to solve this problem. i hope someone will help u soon.