no service from telkom for 6 months

My Mum, a 82 year old is having a problem with telkom landline. you can dial out and receive a call but cannot hear anything due to extreme interference on the phone and the call cuts off intermittently. I have tried my personal handset( working perfectly fine) and i get the same interference,so its a line fault. I Have explained this to the call center personnel on various occasions. Complained about this fault from 8 September 2015 fault refer: ***, 26 October 2015 ***, each time you log a fault an sms is sent to you, i have these as proof. After numerous calls was referred to Lance Malgas(team Leader). 4th Febuary 2016,***. Lance promised to escalate within 24 hours with escalation ref: No. to no Avail. Call 8th feb, spoke to Joe Adakpor, no escalation on system. he gave me an escalation *** within five min. Lance not in. Promised Senior manager will call me, as this was unacceptable,to no avail. however Joe called me to see if management contacted me. Not allowed to give names or contact detail of seniors. Clearly they are not doing their jobs. please help. Paying for no service. Call center operates from Port Elizabeth as per Joe.