Harassment by *********** contract breaking people

After sending a review here I sent an e-mail to MRPmobile collections, There I stated that due to them ignoring my request for payment of costs incurred by me due to their incompetence and breaking of contract, I will be cancelling my debit order with immediate effect. They phoned and stated that I cannot and I told them that they have and security recording stating that , have permission to use a debit order, but now they have it in writing that I am cancelling the debit order and have done so already by the bank. They then said I have to pay by the 1st of every month, and I told them that they broke contract and thus cannot demand from me when to pay. I also reversed their march 1st debit order as I notified them in writing that I am deducting my costs due to their incompetence. They have received a detailed statement of my costs incurred which amounted to R105.00. My payment is R110.00 per month. Now I am being harassed by continuous calls from their *********** staff, saying I am in arrears, yes I am and it started because of their breaking cntract. The arrears is R5.00, but they continue sending sms and phone calls stating I am in arrears with R220.00. This is absolute bull and they know it. I have had enough of their f....ing incompetence and their *********** staff, I will be checking my credit worthiness, and believe me should they report anything there It will be taken further, I am just doing what they did to me. In any case They will receive R5.00 for last month and R110.00 for April when I decide to pay them I have until the 7th of the month to pay and it is my prerogative to wait until the 7th. They are quick to harass us for their payment but can do what they want when they break contract and cause all this absolute bull sh....t , due to their incompetence. They will wait for their money as I had to wait for my costs.