Cash send Refund

On Friday the 13th of October I tried to withdraw a cash send deposit sent via PEP at an Absa atm but got a slip stating that "The transaction was unsuccessful and will be automatically reversed " I then contact PEP on social media (facebook) and explained everything to them ,they started by saying the ID number of the sender was wrong which made me suspicious because the ID number was correct and confirmed seems like they didnt wanna do their job, I've sent them proof of the cash send including the slip from the absa ATM and the cash send Slip from PEP with the numbers to withdraw the money..Now pep on social media is ignoring my messages requesting for a refund of the cash send I never was able to withdraw....I want my money back ASAP...Pep is so unprofessional and doesn't care about the customers queries.