Yet again having problems

Last year in about July 2015 I went to renew my mobile contracts, only to be told that I had to pay an amount to my landline account which was done and the proof of payment was given in to the Gateway Store and this while I was there was sent to the back office and only after fighting I has then given my upgrades, this after from some very nasty comments that where put on their system about me and them threatening staff if my lines where to be renewed they would be fired and liable for legal expenses. I really now do feel like I am being discriminated against by Telkom as I did the online pre-order of the Samsung Galaxy S7 Edge and this was confirmed only now to be told this was not done. I then on the 15th March 2016 went to the Gateway store again for 2 of my lines to be renewed only for it to be referred back to the back office where I now find out before the renewal will be done I have to again pay the amount that they asked for in July last year!!! if they had not received the money why do they now wait a whole 8 months to tell me they cannot find the money and hold up my renewal. All I want is my renewals to be done without a fight!!!