Telkom is useless

I recieved the wireless phone from telkom. What A BIG MISTAKE. I phoned 10210 to help me but seems like they know less than me.The phone is working on your wifi so if you have an adsl line that keep on dropping there is no way in hell that this phone (landline) can work. The best part is I can dial out but cannot receive calls besause it just goes to voicemail. My mum is 82 years old and my son is paralysed from his neck down that was the only communication they had with the outside world but no our landline which we had for years and was working fine had to change to this wireless rubish. I cannot do anything with this phone and they dont want to give me my line back. Telkom is the worst company that I ever had to deal with. THEY DONT KNOW WHAT THE WORD SERVICE MEANS!!!!!!!!!!!!!!!!!!!!!!!!