vodacom fibre are not recommended

i have a vodacom fibre line which ive had nothing but poor signal with. i pay for a 20mb and sometimes get as little as 5mb if not less. i have sent numerous emails to ********** email address and nothing gets done. ive sent through a cancellation giving more than 30 days notice and they still yet to send me a cancellation quotation with zero value. it is now 1 month from when my line shouldve been cancelled and they still havent. i have paid up to my requested final day (10 June 2018). ive included my attorney in all mails i have sent vodacom. pls note i will not pay for any services after the 10 june. vodacom are now saying my account is in arrears and that is their problem. i have run after them long enough. if they try cut all my lines ill take this legal and i will cancell all my lines with them.