When the agent pull out your reservation from the GDS, mistakenly clicked on one of the older profile in their past guest history system with someone have the same name of you but different PC number. It happened to me few times. When the agent change the profile, the credit card information will not change since it is attached to the reservation rather than guest profile.

The reason that the agent can not find your reservation initially may be that the reservation is still in GDS and not loaded to PMS (aka front desk system) yet. You should not worry about your credt card information since the credit card information will be attached to individual reservation rather than guest profile, and only senior management can access relevant information on property. The chance of the information be leaked would be minimum. If you have any doubts contact PC directly.