As per the subject line - my mobile account has somehow got credit limit barred despite showing $0.20 as the only outstanding usage and when I have rung them to try and sort it out I get a recorded message saying that because they are so busy they have closed the queue to avoid people having to wait too long, and to try again later.

I am assuming the credit issue may be because they have tried two set up two handset interest free deals but had to cancel both of them because they couldn't find stock, but either way its pretty awful to not actually be able to contact someone when my phone won't allow me to send a text to the UK to my elderly dad!

I know some contact centres are struggling with wait times at the moment, but to completely close the queue seems crazy and the worst level of service. 

Does anyone know how I could go about getting my credit limit lifted without having to talk to someone?  I cant see that I owe anything on the account so it doesnt seem to make sense that I make a payment, especially since I dont actually know how much that would require.