suspense account help

Dear Mr John Moffat, The cash refund due to customer a was correctly treated in the cash book and then credited to the accounts receivable ledger account of customer b. The above error require a suspense account entry. i think the entries are Dr receivables Cr cash because its a cash refund so B give A cash. so the entries for B would be Dr receivables Cr cash. however they credited receivables which means they have credited twice ( credit receivables credit cash). so the solution is to debit suspense account credit receivables and credit cash. hence this error requires a suspense account. am i correct? Thank you