Cannot reconnect a landline

My mother is 88 years old. My son lives with her and had a DSL service on her line. When he upgraded to fibre, they cancelled the dsl service and Telkom bungled that to the extent that they cut her phone line. Now they want her to get a cellular desktop phone. That is ridiculous. At 88years, she knows only her landline phone and they somehow cannot reconnect the line. Did someone at Telkom forget how to operate a computer and tel the exchange to activate the line again? What can we now do to rectify the situation?