FlightNetwork complaint: Complaint regarding booking MSGDFK

My booking was initially changed and I was sent an email informing me I had the option to go ahead with the flight changes or ask for a refund.
I accepted the changes, and received an email immediately telling me that I would receive my new tickets soon.
A few hours later I received another email informing me that I had asked for a refund and it was being processed.
At no point have I asked for a refund. I contacted customer support who eventually realised that this was an error on your side.
I then received an email telling me that the flights I had originally booked were no longer available, but there were others available on different days.
I replied and accepted these changes, then received an email telling me that my case had been sent to the ‘concern team’ and would be dealt with ly.

This was over 10 days ago. I still have not received new flights, and over the past few days have been emailing and calling to find out the status of my booking and every time I have to inform the operator again about the situation, and then I am told that my case has been sent to the ‘concern team’ and has been marked as urgent. On several occasions I have been told that I will be contacted in 24 hours, but those calls were two days ago.
Every time I call, I am told there is nothing else I can do but wait for the concern team to contact me.

There is no reason for this to have taken over 10 days. This entire situation has been caused by an error on your end.
I do not understand why it is taking so long to book these flights.

I am formally complaining as this is completely unacceptable.
Our flight is (supposedly) in 10 days. We need to know the exact flights and dates for our visas and our accommodation.
This entire situation has caused a considerable amount of distress and frustration.