The new Marvel receiver wires are harder to permanently manipulate with heat than other manufacturers. Most of the time you can go back to your AuD and if they have stock of receivers they can find one or two that has a slightly different bend. Also if your Marvels were shipped to the AuD with the receivers already being attached (something I really hate), the box they put them in can alter the shape.
A heat gun will manipulate best while immediately applying an alcohol wipe to the altered area of the wire.