Jet Mart and Telefunken unable to replace my new TV that broke.

I bought a 50 inch Telefunken TV from Jet Mart in Oxford Street, East london on 01 October 2018. On 01 February 2019 (4 months) the TV stopped working. I took the TV back to Jet Mart as it was still on guarantee / warranty. The manager took the TV and told me the TV will be sent for repairs. They informed me that the TV cannot be repaired. We (myself and the manager) contacted Telefunken to ask if they would be able to replace the TV since its still under guarantee. They informed me that the TV is not being made anymore and the current line of TVs are more expensive so they can't give me a TV. That's the service i received from the two companies. Between Jet and Telefunken something has to beging sorted out so that I can get a new TV. Hellopeter and the rest of the online community can you please help.