Those are not people from avast but a third party that only handles some things for avast.
If you want to complain about it, you need to contact avast.
Since you have a current paid for subscription, all troubleshooting for your program should be for free. NOT! so for a third-party provider for which avast provides a phone number to call.
Their behavior indicates all they want is your money and not provide the help you need. Follow Eddy's advice and complain to avast here:
https://support.avast.com/support/homeOutright suspicious here:
http://avastcustomersupport.com/ Not affiliated with avast. Note the correct names and words are all there, but it is
not avast.
In addition, the 99% error is well-reported as a bug and is known.