Can't locate my payment

I made a loan with wonga in September/ October and made an agreement to pay on the 19th of October but when the dated approached I realized that I won't have funds. I contacted wonga via email asking to change dates they refused. Long story short I phone to make payment arrangements on the loan. I made a first payment of R1000 on my R2583.00 loan. And balance remained was R1583.00 which I later settled on 26/11/17. I paid via mobile bank. Til this day they can't locate that amount even after numerous proof of payments. They have escalated the matter to legal collectors. This morning I woke up to a debit order of the same amount.!!! My bank confirmed that the amount went out to wonga and they admit they didn't receive it they must send proof. Till this day I'm waiting. When I phone they customer service number it never available just goes straight to collection dept. They too are useless.I want my money back !