Unsubstantiated claims of waster damage on my phone's warranty claim to avoid repair costs

My Samsung Galaxy S24+ phone suddenly stopped working around mid December, with the power button not working and the phone not picking up any cellular network, meaning I could not make calls. Phone has a 24 month warranty, so I took it to a Vodacom repair shop, where I was advised that it'll be send to GP for repairs. Got notification that the phone is back, and when I go to fetch it, I'm told that it was not fixed as the issue is due to water damage. When I check the phone, it seems that the phone was not even disassembled as the phone was in the same state it was in when I took it in. No evidence whatsoever of the "water damage" was provided. I was just shown a hand written once sentence on the job card as "feedback".

This means that they can just take your phone that is under warranty, "assess it" and provide whatever feedback that'll absolve them of any accountability or cost of repairs, then give you your phone back, then ask you to book it again for repairs at your own cost. The phone was kept in an immaculate condition. If that is your claim, back it up with technical feedback, and when I asked for this, none was provided.