On the "Earn Free Credits" page, there is a button at the right hand side labelled "Support". Click that and it will email WGT about the issue who will then be able to verify your claim and apply your credits (they did for me).
I don't know if you are aware, but it's WGT who gives you the credits not Quote Sonic, so contacting the Insurer about the non-issuing of credits is pointless.
HTH.