Government gateway issues

[kiethton]

Been trying to claim my tax overpayment via the government gateway for the past few days. Each time I try I enter the information, generate the code etc. and get a message "service unavailable please try again later". Its only a few hundred quid so not huge, but rather annoying, typically their live chat function also shows the "sorry due to demand nobody can speak to you, please call back later".

Any way of getting this resolved? - is it a case of just trying repeatedly?