Hi this has happened to me as well - did one off payment but still telling me i'm in debt. What happened with you with this situation? How did it get sorted? 

I guess it takes a few working days to get fully credited to your account, bound to be slower during public holidays. 

Hello,

I want to make a One-Off Payment but the button is not there anymore!?! What can I do?

@Enrik120483   Hi, if you are using the app, or web browser on a phone, some of the menus have changed recently. If you use your web account on a tablet or laptop that does seem to work. 

Hi I feel your pain! Scottish Power left me without a working electricity meter for over a year, they failed to install a new meter on about 5 occasions. I had to go to the energy ombudsman. Only then did I get a working meter. They sent a bill for £205 just after the meter was replaced the ombudsman said that was fair. They ruled that Scottish Power should pay £240 for missing meter installments as Ofgem's Guidelines and £100 good will gesture. Scottish Power appealed but could not provide proof of adequate notice of appointment cancellations so the original decision was upheld. Mean while they put up our energy prices and are blocking us from leaving them. Today I discovered they have increased the original bill from £205 to £559 but they have deducted the £100. How they think they will get away with that i do not know. I have contacted the Ombudsman Ofgem Watchdog and I am now looking into filling in a small claims form to take them to court. Changing the bill is fraud so I am going to look into criminal proceedings for that too.