Please fix SMS problems.

I'm almost gonna quit using my account, at the brink of it at least. I don't get SMS problems with other sites except discord. I've been trying for a while but I can't, (I've already messaged support team waiting for reply at the moment)
I'm not sure if I have two accounts with the same phone number but if two accounts have the same phone number then why does it still not send sms to phone? To that one number? Is there seriously nothing you can all do to fix it?