Receiving a que call while on a regular call.

We have very expensive marketing calls coming in and our agents know they will not receive a marketing call if they are on the phone. Because ring central takes them out of the call que. So they do not use the ring central phone to make their calls because it takes them out of the que. I need them to receive marketing call while they are on the ring central phone. In our business we use the phone all day and it encourages the agents to want to be off the ring central phone waiting for a marketing call. This is about to be a deal breaker for me.