A homeowner is facing issues with a builder who incorrectly constructed the foundation, leaving insufficient space for a car park. Despite the builder acknowledging the error and promising a solution, the car park space has not been provided even after nine months. The homeowner has withheld full payment and is seeking advice on legal recourse, including serving a legal notice or filing a case with the District Consumer Forum or RERA. They are also exploring a mutual agreement for shared car park space.