Pathetic customer service from Vodacom Business

We have been trying since last year to cancel the contract because the contracted period is over. Vodacom has asked us to send a letter which we did and there has been no response. Countless phone calls to vodacom business was fruitless because the call is always dropped. Now vodacom has blocked all phone calls to the cellnumber. We cannot go to a store because they will tell u to contact vodacom business. What a waste of time and money dealing with Vodacom Business