I need to formulate a "polite" response to the companies who supply the company who I work for when they complain about the prices we are selling their goods at.

They want us to sell close to or at RRP, believing it devalues their brand if we discount.

This is known as Retail Price Maintenance or Price Fixing.

Some companies in the industry I work in have been fined for Price Fixing in the past and I don't want mine to be caught up in an investigation.

Any suggestions?