Citroen dealer, a written quote, an incorrect part number and refuse to take it back

As a pensioner, I bought a great little Citroen C1. The power steering unit failed and I went to the Citroen dealer and was given a written quote with the part number. That dealer closed down and I bought the part from a different Citroen dealer. I took the part to a Citreon dealer to fit and after fitting it they informed me that it was the incorrect part. To myself that was no problem, the dealer returns the part to Citroen SA and the correct part would be supp****. Citroen SA refused to take the part back into stock and I had to buy another part for R6 695.79. Now I have two Power steering Units and the incorrect one is one display in my house for my friends and visitors to see, with many questions about why I have a motor car part on display! I then contacted the Motor Industry Ombudsman and there reply is " Afte a number of attempts to acquire a response from the supplier have failed, we conclude that there is no reasonable probability of the parties resolving their dispute through the process of conciliation and the MIOSA, therefore, terminates the process."