Vodacom
VODACOM! Very or NO Reception

I'm fed up with VODACOM bad reception!! They already came out and put an extra big areal on my roof but for no success.
I'm working from home, but I can't phone my clients or if they phone me they can't hear me! It makes me look very unprofessional!
But even worst, if my clients come to see me they can't get in at security because security can't get hold of me!
And they don't want me to cancel my account, and then I have to pay one of a fine!
I can't get Telkom because we don't have Telkom lines here by us! I do have Cell C Internet - and that works 110% so why can't Vodacom work 110%.
Please HELP!