VERY POOR SERVICE!

I have been a well paying customer for a long time with Wonga but I still have to raise the same issue I once faced.

I had 2 accounts with them, one which I paid off and sent the POP via email asking them to receipt my payment and close it. They advised it would take 3 working days for the account to show as closed on my side but it went on for more than 5 days until I followed up and it was closed. The other account is open and active an installment was supposed to be deducted from my account, instead an installment amount for the old and closed account was taken out of my account on the 1st. I then sent an email correcting them and requesting a credit in my bank acount so the correct account could be paid. Today is the 5, I have been following up with them everyday, and now I am getting an SMS stating that I have an outstanding payment and will incur an additional debt collection charge of not paid. This is infuriating because if the requested amendment was done on that same day I asked for it to be done I would not be in this position.