"HMRC said the number of cases would reduce as the new system beds in."
"Last year, HMRC identified 4.3 million people due refunds for overpayments and some 1.4 million who owed the taxman after paying too little."
I'd say it's getting worse not better

Wonder how much will this latest balls up end up costing the tax payer!
BBC News - Millions more in line for tax rebates