The last presentation of this course starts in September and registration is closed so you have missed out on it.
The ACA do some sort of certificate which takes a year and you can it do distance learning and do the exams pretty much whenever you like which may be suitable for you but then you will need to find employment straight after that year (so if you cant get a paid job look for free work experience whilst your doing the certificate so a firm will be more likely to take you on when you hvae finished it). You may be able to use some of your uni modules as exemptions.
You could also use the credit transfer method with your previous uni study and count it towards a business studies with accounting degree at the OU.