No, you are not required to give a refund if you are providing the services or available and willing to provide the services (and they are at a professionally acceptable level) and the customer simply wants a refund. The law does not require refunds when the services are provided, but only when the provider fails to provide what they were supposed to, or the services provision are reasonably unacceptable in quality. The exception would be if the service agreement/contract/terms of service, etc. included a refund policy; if you voluntarily put out there and had a refund policy, you have to honor its terms.