Hey there and welcome to the Samsung UK Community Forum
Sorry to hear of your troubles.
If the device is out of warranty (which from your post suggests it might be) then realistically you have 3 choices.....
1. Pay for a repair
2. Replace
3. Consumer Directive 2015
The last option would likely fall into to options:
1. Is the product of merchantable quality...I.e. would it reasonably be expected to last more than the 3 or so years you've had it and
2. Are you able to prove the fault was there at the point of manufacture.
Your promise of a call back? We have seen so many posts about this from other users where the call never comes. I hope it does for you.
Sadly I suspect Samsung Customer Service won't help (from the posts on here) so you may have to consider resorting to making an application through the Small Claims Court for recompense. Samsung may decide it is cheaper to accept the claim, but they may also see they have a strong case as the device is out of warranty.
Only thing left is to see if you have any evidence supporting 5 year warranty. They do use this as a promotional tool from time to time.
S24 Ultra