Can't get a refund- being going round in a loop since 2nd December!

It seems impossible to contact Avast again- I was talking to someone who offered a comprimise, but who then cut me off. The software number then disappeared from my list of purchases so I can’t use the online refund process!!!

This is appalling - as I have said , thishas been going on from December 2- the 30 days has passed- but nothing has come through!