Reopen and review 2020 tax return

I was audited for the tax year of 2020 and IRS wanted proof of my dependence and my earned income credit so I sent him the paperwork I thought was adequate only to hear back from the IRS a couple months later stating they never received the proper paperwork and rather than get my $9800 return I owe them 6500. I haven’t filed my taxes since that year because I am getting robbed and I need help to have that year reviewed or reopened or fixed because this may be incorrect but I recently was told if I don’t have that year fixed I will not be able to get earned income credit for six years after that. Please please help me :(