I have a few large heavy items that we sell that cannot go UPS or USPS so we use trucking companies for them and charge a flat rate, however even though the flat rate is displayed as an option UPS and USPS both give the option of shipping the 150+lb product for $9.95 (I’m assuming a default?)
How do I remove the UPS & USPS options from shipping these few heavy items and just have the flat rate?