The Courier Guy is not playing fair!

I used our business account with The Courier Guy to book a collection for a same day delivery. Despite the parcel being ready early enough for that service, it was only delivered the next day. I emailed their support centre and received an email back saying the waybill would be investigated. Since then I have emailed and called but I have not had the courtesy of a response. Our business account was invoiced for the same day delivery fee which, if they had any integrity, should have been amended to the cheaper rate. This is my second incident with shocking service from the support centre. Time to find a new courier for our business!