JulHa:
Would it help to change it to
int c = client.read();?
Nope.
if you are receiving a byte value of 10, then use real numbers ( not chars ) in the switch.
If you receive two chars I.e "10" then you need two reads.
It doesn't work now because of value truncation.
First '11' is not the same as "11"
These statements are true due to truncation:
'0' == ( char ) '10';
'1' == ( char ) '11';