Faulty warranty A51 Phone repaired multiple times. Not been swapped out.

I have a Samsung A51 Phone. Still under warranty. It has been repaired twice this year so far. It is still not functioning correctly. I have not had proper use of this phone since it broke in December 2021. Each time I took the phone in to be repaired I had to make use of an old faulty S6 to function which does not have the capacity for all my data. The A51 currently does not work correctly on the MTN Network and requires constant restarting for it to register correctly. The S6 phone however works fine. I am having to use the S6 for MTN connectivity for voice and data. I hot swap the A51 off the S6 for banking, whatsapp etc. The A51 has very important info on it that I require for a court case so I can not give the phone up as Samsung can not give me an eta as to how long they will take to now supply me with a new device, considering that they have already had it for more than 2 months this year alone you can understand my concerns. I do believe according to the CPA that they are now obliged to refund or replace the device. This is the second time I have had to deal with this abysmally poor service company. Once again, there will be an automated response on 'Hello Peter' from Samsung. lets see how long it takes them to resolve this one. The last time it took them over a year to resolve an issue with this same phone.