Mine is very similar to this..
Best answer by Amy
Welcome on the community and thank you for your question. It's unfortunate to see that you have scratches on your P20. :(
Scratches or damage to plastic surfaces and all other externally exposed parts due to normal use are not covered by the warranty. Please make sure that there is no sand or anything between your phone and the case, to make sure it does not get worse. You can read more info on warranty on this page.