New wifi telephone service

Telkom changed my landline to a wifi line, as the regular landline will be discontinued. I had not actually placed the order, but that is by the way. I have now this new device which has a very bad background noise to the point that people often do not understand what is being said. There is interference from the printer, the computer, etc., but I need the phone to be near my office equipment. Have tried to speak to Telkom call centre, but nobody has any technical knowledge. I bitterly regret having this new invention from Telkom.