Dents around Macbook air

..While protective cases may seem like an idea to help

this might not be good, due to heat build-up retention

since most cases are too tight and offer no ventilation.

Most cases are not recommended by Apple; even when

previous versions may have been offered by 3rd parties.

[Given newer hardware designs' need to conduct heat

direct to surrounding air; your choice remains to handle

the metal encased portable Mac, with much more care.]

IF damages result from travel, then use an external case

& remove that before use. Be certain the MB/Air is "Off."

A repair might involve replacement of the entire case$$.

We are apple users, not apple itself. Please Contact - Official Apple Support to set up hardware service

Considering this happen in three separate places, I suggest you just live with it. If this is happening often enough for three dents, it's likely keep happening.