Evotel/ Supersonic

For my wifi that was not sorted out, was promised 20 meg line from Evotel. And got a 10 meg line. Was not promised what we signed up for. Now Supersonic has given my personal details to the Dept Collectors to collect the amount. AFTER I HAVE SAID TO THEM I WILL NOT PAY THE BILL UNTIL I GET MY 20 MEG LINE. After numerous telephone calls to these people Supersonic says I must speak to Evotel. Evotel says I must speak to Supersonic. And NO ONE has called again. So to hear all of the people that i have spoken to over watsup at Evotel is no more employees of Evotel any more. So nou wat nou?????