As you might not be able to get matching doors a shelving system may be a better idea. You can get strips that run the length of the wall and the shelves sit onto brackets. They didn't have a great selection of wood for the shelves when I looked at them some years ago and they could work out quite expensive also. Most of the larger stores like Woodies used to do them.
Its a pity the people
measuring up/installing the wardrobes did not discuss your options on this. They might have been able to do matching shelves.