Extremely poor service

Previous cases still waiting and gave up. I logged a case, number ***7, on 4 December and have yet to hear or see a tech. Live next to a 3G tower yet have extremely poor reception, pathetic hey. up until a year ago the signal was perfect. Been in constant contact with Telkom on FB and lots of feedback without any action. Have just taken out 4 more contracts. Do I cancel the contracts for non-delivery? Please advise urgently