I only take cheque or cash and haven't had any issues. I have a fee for bounced cheques and have only had to charge it twice but in both cases they told me about it before it happened but unfortunately I had already put the cheques in the bank so I was still charged. My fee covers the charge from my bank plus a bit extra for the inconvenience.

5-7 business days seems long to me. Have you spoke to your bank about the wait time for cheques to clear?