Ghost company

We bought a car with Marquise Finance 09 February 2024 and is not balloon payment but on February 2025, they changed the instalment amount without notification then it bounced. Then they complain that we did not pay February 2025.Another problem in May 2025 we asked for settlement amount they gave us R158654.00. This can not be right because when we buy the car it was R146900. and we signed the agreement with Marquis Finance to pay R168602.50.We paid the car R3600.00 for 14 months which came to R57600.00.Now if you minus that from R168602.50 its giving us R111002.50.So they insist on R158654.00.When we ask for their address they saying because we wanted to come their offices .Everyone of their agents says its in Bryanstan when we ask were in Bryanston they don't know.