I did everything you suggested and Avast scans stick at 0% except now quit scan doesn’t work either…Uninstalled using Avast clear in Safe mode and did offline install…no luck…
No Refund from download crew or Cleverbridge either…
I would suggest that you remove your email address on a public forum, it could be harvested and added to spam lists.
Support Ticket Refund - https://support.avast.com/support/tickets/new?form=2
Though I don’t know how useful that would be unless downloadcrew are authorised avast resellers.