Just like any large business with many branches, there will be good ones and also some bad apples.
As many have stated here, it depends on the branches and whether you are unlucky enough to catch the staff on a bad day (yes, unfortunately, not everyone is professional).

Personally, my experience with Public Bank has been very positive over the years.
Three months ago, I went to change my debit card at a PBB branch in Ipoh. It was Chinese New Year period and the place was packed to the brim. I did have to wait quite a bit before it was my turn, but the staff was still very polite and helpful, and helped me with my debit card replaced in just a few minutes, then guided me on how to replace my PIN number, etc. and all the while with a friendly smile.

Of course bad and impolite staff exist as well, but I prefer to believe that if I approach the staff with a smile and friendly attitude first, most times they will reciprocate.