Collections department keeps on calling although the payment is made on the account at the ****en store

This is ,my 3rd time complaining about Vodacom and their ridiculous service . This company is so unprofessional . I am my arrears to the store every month but they keep on calling me every day that they do not see the payment on their side. How so when the payment is done at the store. Their consultants advised that if you do payment at the store it reflects immediately but that is not the case because they keep on calling me harrasing me when the payment is actually made , I cant wait to clear my arrears and never upgrade with Vodacom.