Poor internet reception in area of my home

I signed a contract in which telkom mobile under took amongst others to supply me with 7.5 gigs of mobile internet after hours included in the contract price of R299.I get almost no telkom mobile data coverage after hours.I have reported the problem to the walk-in centre at Kolonade Montanapark a number of times.The technical people have come and checked out the reception and have agreed that there is a problem.However no action has been taken to rectify the problem.I have also been in contact with the call centre.This problem was first reported in January 2014 and repeated a number of times since.I am completely worn out complaining to Telkom mobile.They are not meeting our contract and don't appear to be concerned about me as a customer