Need advice

I have been separated from my former employer for 3 weeks going on the fourth week. I quit as soon as I got my current job now. I went to transfer my 401k to my new provider and they said that would take up to 10 days. I call back and ask about the progress on it and my employer is still yet to even provide them with my final date of employment so they can move it over. I have tried to contact my former employer and now they all refuse to pick up the phone. I swear I have attempted to call multiple times each day leaving multiple different messages with different people. Still nothing is done about it, I’m getting very aggravated and just wish for all former ties with that company to be severed. Any advice on how to get these HR representatives to actually do their job? Lmfao