I cannot delete my old iphone 4 icloud backup. Message: "This backup cannot be deleted as it is in use"

Yesterday, I used my iphone4 icloud backup for my new iphone5. As the wifi connection was unstable I experienced problems. So I backed up my iphone4 on itunes. I reset my iphone5 and used the itunes backup. I now cannot delete the iphone4 icloud backup. I have turned off "back up" on both phones. I have tried deleting iphone4 back up from iphones, ipad & imac with no success. I have read that you need to wait 48 hours as icloud is still backing up? I cannot backup my iphone5 as there is insufficient storage.