Worst ISP ever!

Supersonic Fibre must be the worst ISP I ever had to deal with. It's been nearly 4 weeks of constant communication and absolutely nothing has been done. They promise you that they will get back to you and they escalate the case to management, but still nothing happens. No feedback. You can't speak to the cancellations department as they are "untouchable", you have to speak to Customer Service, who can't do anything - they just try to pacify the client with lame excuses. The previous owner had a subscription with Supersonic Fibre which was cancelled according to their standard procedure, they even had to pay cancellation penalties - the account has been cancelled and all invoices paid. Now, it's a matter of releasing the line to Openserve so that my ISP can claim the line and connect my Fibre Package. To this day Supersonic Fibre hasn't released the line and keep on giving thousands of lame excuses for this unprofessional and ********* behaviour. I fail to understand why they can't just release the line, they don't bother to phone you with feedback or progress, they *******ly keep the line "locked" in order to avoid other ISP's to claim the line!!!! I am currently spending thousand of Rands on mobile data just to keep on working and to keep students connected to complete online exams. Stay away from Supersonic Fibre - they are the worst ISP you will ever get... unprofessional, ********* and absolutely pathetic!