Advance Payments UC

I dont know if she can, shes on leave at present. I know our C/Tax reduction changed this year to 95% from 100% due to council disability reductions. We had to pay the extra, which we did in one payment as not wanting a debt. Then this morn I had a c/tax message regarding our previous address from 10 yrs ago. No idea whats going on i've emailed Sutton Council to ask & also messaged UC via journal, but no replies. UC say theres a problem with SMS messages. So no idea whats going on. Very confused & stressed