Virus Scans don't work

Hey, I’m very frustrated right now, when I try to run a full virus scan, or even when I set up a custom scan that scans my whole computer (all the files) it doesn’t do anything, it just sits at 0%. I can run a quick scan o.k., but that’s not good enough for me. I want to use the full scan every time. I have already tried updating it, repairing it in the uninstall menu, and uninstalling it and re-installing it. I paid $40 for an upgrade to a better version, and the damned thing just stopped working on me. I can’t even get any help, $80 just to talk to somebody is ridiculous, I don’t even have a phone, but I have a computer and I need it to function properly. I’m rightfully pissed off, I paid my money, for what, a couple weeks of virus scans? This is supposed to last for a whole year, I feel ripped off, but all I want is for the full virus scan and my custom scans to function and not just sit at 0% forever. Last night, before I went to bed, I started a full scan to see if it would be finished when I woke up, I woke up, and there was nothing at all, no open windows, no scan results, nothing, like it just gave up or something, decided it didn’t want to do the scan. What is with this crap? I would really appreciate if somebody could help, but what really could be done that I haven’t tried already? If you can help, please, I need some help. I’m going to demand a refund or something if nothing improves, cause, what else can I do? It’s not fair, I’m a paying customer.

Are you sure it is not scanning, meaning it is just a gui (0%) bug?

I woke up, and there was nothing at all, no open windows, no scan results, nothing,
Did you check the log?
I want to use the full scan every time.
Why ?
I can't even get any help, $80 just to talk to somebody is ridiculous
Help is free through the ticket system as well as here on this webboard.

Why are you running a full scan ?
There normally is no need for as avast has the real time protection.

Why the OP is running an on-demand scan isn’t important (I don’t run them either), what is important is if the on demand scan is run then it should work.