I'm very impressed with my new iPhone 5C but it has a major flaw... the plastic back is slippy as hell! I've dropped it like 10 times in the last week so ended

I'm very impressed with my new iPhone 5C but it has a major flaw... the plastic back is slippy as hell! I've dropped it like 10 times in the last week so ended up having to buy a case. At no point during testing did it slip out of someones hand?