BILLING incorrectly

I have been BILLED incorrectly twice in a month every time I CALL I get told an escalation is send I should wait 24 to 48 hours each time since the 20th. Mind you I'm on maternity leave and BILLING me incorrectly causes more trouble than anything. I don't have the airtime to call anymore. I've called.emailed. sent Facebook inbox and on their website still not resolved.