Telkom SLOW internet for years - can't even reach them to CANCEL my contract!

Absolutely SLOW SLOW SLOW internet connection, nothing is loading, can't even go onto internet to load a page to see where I can complain to Telkom. Getting absolutely NO work done from home with this terrible slow TELKOM internet. How and where do I CANCEL my Telkom contract please, so sick and tired of years of pathetic service with them! Anyone reading this please suggest some fast reliable wireless companies and internet connections for me. Thanks.