Can't change phone number

some time ago, I started affiliating. I forgot the number used for this account was my old phone's. And I lost that phone with the sim card. Now, I'm trying to change the phone number. This has happend only the second time. I tried doing this some hours ago but the same thing happened so I tried waiting a few hours to try again but it's still the same. Anybody got an Idea how to fix this? I'm just Trina get the earnings from my affiliates