有關租客按金問題

Yes. This is a contractual obligation of the landlord. The tenant gave out the reason that no cheque had been received and the cheque is still a fact not yet presented for payment. This is a fact that the rental deposit still not yet returned to the tenant. Now, you should send a new cheque to the company by registered post and with the acknowledgment of the cheque signed by them. So, no reason for non-receipt of the refund of the rental deposit be given again. And, you have taken a positive step to clean up this dispute by performing your part in good faith.