Air carrier flight crew reported the fuselage surface around an aux static port had peeling paint and the attempted repair made the situation worse. The flight crew refused the aircraft.

Narrative

The First Officer (FO) completed the walk-around; came back inside and showed me a picture of the Aux Static Port which had paint chipped around the black ring and big chunk of paint peeling just outside the black painted ring. So; I wrote it up. The mechanic that came out to look at it; told us he had completed a repair; so my FO went back out and took more photos. The photos showed that the mechanic had placed 5 strips of speed tape over the area in question. I told him that could not be the correct repair for this issue since the speed tape would affect the laminar air flow over the static port (which is a critical area for our instruments); which would then give us erroneous information to our Standby Instruments. He insisted that this is what the mechanic in Maintenance Control told him to do and it was a valid repair. So; I called Maintenance Control; talked with the mechanic; sent him pictures of the before and after pics; and he told me that is NOT what he told the mechanic in ZZZ to do; then told me the plane would be grounded. Eventually; the senior mechanic on duty in ZZZ came out to our plane and told us he was in discussions with Maintenance Control about getting a different type of repair or approval completed for that plane (they had taken the speed tape off the static port area; which created more peeling paint). We were told we would be switching to a different airplane; so did not take that plane.Cause: While this was only an issue with our Auxiliary Static Port; which provides info to our Standby Instruments; it is still a critical area which should be clean and clear of anything which could affect the information provided to our instruments. The mechanic's lack of understanding this is a safety issue; especially since he was insisting that the speed tape was an acceptable repair. Had this been the static port for the Captain or FO's instruments and had they taken the plane with the speed tape; I believe they would have had erroneous information on their instruments. Best way to mitigate this problem in the future is to provide proper training to the mechanics so they understand that this area is a critical area for our instruments.