I am so frustrated with the terrible service

I am so frustrated, I've been trying to get a settlement letter since last week I keep getting transferred from pillar to post using my own airtime. My account is in arrears and about to be handed over to legal so I want to settle immediately but I am not getting any assistance, I was told I'll get the letter within 24 - 48 hours but nothing, today I call again and I've been on hold for more than 30 min with no one assisting me they still transferring me from pillar to post. Even after I told them I'm going to complain about it, so this is my last resort, and bare in mind should my account he handed over i won't take full responsibility for that because I want to settle but RCS does not want to send me a settlement letter via pdf