Discovery Card OTP support a shambles

So I call discovery card to ask them to change my contact number since I've recently changed my number. I tell them the new number. They say that the OTP team will call in 24-48 hours. After 2 days I call them to tell them that I haven't received a call. They say it's supposed to be 3 days. I wait. Then I get an email that they have tried to call but can't get through. Turns out they are calling the old number. I call them to tell them that my number has changed they need to call on the new number. They tell me they will call in 3 days again! I ask why and they say a new ticket needs to be created as the old one was closed! How do you close a ticket if issue has not been resolved?! Really disappointed that it's taking almost two weeks to get them to simply change my number so I can get OTPs on my new number.