1. fee payable and fee refundable (itshould be: payable and non-payable?)
2. cheque payment (payment by cheque)
3. increase of fees (increase in fees)
4. However, you cannot submit more than six documents at a time.(..., you can only submit a maximum of six documents each time. or any better expression?)
5. How can I ensure that the company has received my documents submitted by post or through the Drop-In Collection Box? (How can I know whether the company......Drop-In Box?)
6. What are the requirements for making an application for refund? (What are the requirements to apply for a refund)
7. Can I submit an application for refund by fax? No. You can submit your application by hand or by post. (No. You can ONLY submit your application in person or by post).
8. Failure to do so will make the company liable to prosecution. (Failing that (or Failing to do so) the company will be liable to prosecution?).
9. For related information,...(For relevant information,....?)