Bad service from Wonga

I have been trying to sort out my inquiry since 28 June 2019.

Payment was made for the monthly installment and Wonga says they never received it. Payment was not done via EFT it was done by a debit order Wonga loaded onto my bank account. I contacted my bank and they confirmed that the debit order was successful. I have been trying to sort this out since June. Emails was send, phone calls was made and every time they say the financial department will phone me back. Until today no phone calls from Wonga's Financial department was made to me.

Can someone from Wonga please contact me so that we can sort out this issue. As the loan was paid.