Stock on back order

Almost 4 months later and my vehicle is still not fixed On the 28/01/2023 I booked my vehicle in a Kia weltevreden due to a noise coming from the transmission (manual) they then diagnosed the vehicle confirming that the transmission needed to be replaced and advised that it would take up to 21 days to be repaired. After the 21 days had passed I called to find out when i could collect my vehicle and was told that it had not been repaired yet as they do not currently have the transmission in stock due to it being on back order from Korea. I'm am extremely dissatisfied as I had to do the following up and was not contacted promptly and informed about whether or not they have received the transmission. I was then offered a rental vehicle by Kia, which I was liable for to pay a deposit for. This issue has now been ongoing for close to 4 months and I am paying insurance and installments on a vehicle which Is not even in my procession. The rental which I was given is too small for me as I have a newborn and a 5year old that needs to be driven around and I can't even fit a stroller in the boot. I have now made numerous phone calls to Kia weltevreden as well as Kia customer care and no one can even give me an ETA on when the vehicle will be fixed. I would never recommend any one buy a Kia ever as this is the second time the vehicle has been to Kia for transmission related issues. I am extremely disappointed in Kia's service and I hope this will be over soon so I can get rid of this problematic brand and never have to deal with them again. I hope to hear from Kia sooner then later so we can cut ties and I can go back to using other brands of vehicles that will offer me better service