no network coverage, call the call centre, no help

I have been a valued customer for over 10 years now at MTN. I have never had any problem with my signal, i have 3 contracts all mtn. Since they started the strike, i have been having no signal or 1 bar signal on my phone.I am self employed and use my cell phone for business. When people phone me, if they can get through, then while im talking to them the phone just cuts, this is xtremly bad for business. I have phoned the call centre and the coverage people on several occasions and all they say is a tower is not working,they are working on the problem,. This is now over 4 months with the same problem. It is so bad that i had to get a vodacom prepaid so that my customers can get hold of me. Cant anything be done about this, or is it time i should change????