Hairline crack again

Good day

My first iPad dated ********** 7 develop a hairline crack with lots of fighting with Apple it was replaced

Date ********** 8 my 6 month old iPad Pro 12.9 another hairline crack on side 20mm from the black side appeared ......

are there something wrong with these iPad pro12.9

Why do they have these hairline cracks

I use the Apple Pencil with the iPad 12.9 and I’m very confused and disssopointed paying R23734 for it and this happens R1908 us dollors

My first 9inch Ipad never had these issues now using these the big iPads there must be a disadvantage on the quality on the glass of the iPad Pro 12.9

Please assist in the matter as I would like to continue using these products but I am very concerned