I've been with TPG mobile (Pay as you go plan) for nearly a decade. Recently I found out that they were charging my account for Voice mail I never subscribed to or used. I checked my bills, calculated the amount- around $60, made several complaints (5 of them are with ref. numbers), and received no refund. Every time they register my complaint about this issue, they say to wait for 2 business days, then they don't reply nor refund and can't find the complaint on my file.
I don't get any SMS messages that I received voice mail. What I get is ongoing charges for this non-existent service. After several complaints they still keep charging my account for voice mail.
PS. After my emails to TIO resolution with cc to TPG execs, TPG finally reversed the charges.