I am very disappointed in wonga loan.

I am very disappointed in wonga loan. i receive a call of discount to settle my account 2020/06/20 with discount which i can afford and i accept , they run a debit order from account with that amount , and they still hand me over for collection now ,my account is no settled , i have bank statement as a proof but the collection department want a proof , how do i get proof of debit order beside statement , yaah neh tis is hard honestly.