Bad service

I have a contract account with Telkom They've debited my account on the 20th Of June 2018 and it went through successfully, now I am busy receiving collection messages that my account is in arrears while I paid on time this is bad service I've spoken to 5 agents already even went to a store I'm still not getting anywhere they even have the tendency to make it seem like it's my fault I've got nothing to do with how your system works, I paid on time now allocate my payment and send an update on my credit profile because it'll be affected by your negligence I made a transition from Cell C to Your company but now I'm regretful I am not stopping until this matter gets sorted out! This is pure bad service.. 10 working days has passed already..