Terrible service

I made arrangements with CWX representative of finchoice and arranged for the debit order to be canceled, I will settle the account the following day. The lady promised me it won't go through but it did. I paid the settlement and later realized I made a typing error and the ref was one number wrong. I sent them proof of payment to reallocate the funds to my account and close the account. They make it so impossible to allocate the funds. Finchoice please intervene I'm scared the might charge me interests after 7days cause no money received for this month as I reversed the monthly installment. CWX doesn't even call me, whenever I call and ask for the lady CANDIS who I spoke to, they say which department, where does she work and I can't answer that as we don't ask where the consultants are based