peugeot 206 brake pad

Hi, am new to this board and hope someone can help me with a problem I
have with my daughters Peugeot 206, 1999 1.4. non ABS
She bought the car a year ago and I fitted new front pads as on the
offside, the outer pad ( other side to the cylinder) was worn more
than the others.
Two months ago the very same pad had worn down to the metal while all
others were nearly new. I checked the cylinder retracted OK, slider
was free. I fitted new discs as well as pads this time.
I have just had a look, and could not believe it, this same pad is
starting to wear at a faster rate than the others.
I am at a complete loss ! am I missing the obvious??
Any help would be gratefully recieved
Regards
Tom

 

There might be a spot on the brake cylinder that is not letting the
piston to return,it might come out o,k but it might go back a little
way,so try and get it to go back all the way,

 

Ta CHRS, will give this a try. If this was the case though, would the
pad nearest to the piston not wear quickly as well or instead of the
one opposite the piston ??
Thankyou for taking the time to assist
Regards
To