Dell computers lack of customer service

On 30 May 2021 I went to HiFi corporation and bought my 2 11 year old sons a Dell 23.8 in monitor each - R2299.00 each. Two days thereafter my son moved his monitor by touching it on the tip right hand side of the screen! It seems the LCD inside cracked. No force was used!!!the receipt clearly shows a 3 year warranty. I contacted dell computers and they told me they cannot replace the monitor as this is customer induced!!! This is clearly a case of daylight deception! My son is 11 years old - he did not drop the screen!!! How much strength can he have to break a screen!!!! The only conclusion I can make is that this was a fault in the batch production. Can someone please help me!!!!!!