HerRoom Response: If you have an under-bust measurement of 42, you need to add 4" to get your correct band size. Therefore, you would be a band size 46.
HerRoom Response:Longline bras are always a challenge for plus size women. The manufacturer selects a bust size, then determines what the most common waist size will be and makes the garment accordingly. If your waist is considerably large, there really is no long line bra on the market that accomodates you. One solution would be to wear a bra and a piece of shapewear.
HerRoom Response: We are sorry that this item didn't fit you. At HerRoom we use the terms "full figure" and "plus size" very carefully. Full figure means bra sizes larger than a D cup. A full figure woman has full breasts. Plus size means breasts larger than a D AND panty sizing larger than a 9. A plus size woman has full breasts and more "meat" on her bones.
HerRoom Response: It sounds like you could successfully go down a size or 2 in this garment.