It is completely unacceptable that you have kept your customer's credit card details. You are completely violating Requirement 3.1 of the latest PCI-DSS (which has been the same since I looked at v2.x of the standard, incidentally):
3.1 Keep cardholder data storage to a minimum by implementing data retention
and disposal policies, procedures and processes that include at least the
following for all cardholder data (CHD) storage:
Limiting data storage amount and retention time to that which is required
for legal, regulatory, and/or business requirements
Specific retention requirements for cardholder data
Processes for secure deletion of data when no longer needed
A quarterly process for identifying and securely deleting stored cardholder
data that exceeds defined retention.
These standards can be found here:
https://www.pcisecuritystandards.org/documents/PCI_DSS_v3-1....You might be trying to reboot your business, but your Comms didn't say that you were dealing with the same company owners. You also appear to have ripped off a competitors website.
You don't sound very trustworthy or reliable. If you can't keep to at least the PCI-DSS standards, what makes you think anyone can trust you moving forward?