Instead of using MP7 for parcels to USA, I now have to use MPR in order to be able to pre-pay the USA Tariff. However, the compensation level on this is only £50, when on MP7 it was £150 I believe? Why is this?

The reason I am asking here is because communication with RM is virtually impossible. Phone calls take hours to be answered and emails more than a week, if you receive any response at all.