Asked 4 Mand Recon No decision waited 5 months +

Hi.
After a terrible face to face assessment last April, I was informed by DWP that I was being moved from ESA Support group to the WRAG group.
I wrote a long letter with list of reasons why I believed I should be in Support group and asked for a mandatory reconsideration. I kept postal receipts etc they received my letter 6 June.
To date no letter to say whether they are upholding their decision or changing it.
I have called quite a few times now. Some times I have had to hang up as just on hold for ages. Finally got through 3 weeks ago. Bearing in mind I have now spent around £50 on phoning them (on my mobile), First person I spoke with saw that my letter was looked at around 26 July. No decision made. She escalated my call. Nothing happened.
Second person I called sounded very sympathetic to my situation - he escalated call said someone should call me next day. I received a call from someone - it wasn't the decision / processing department - they just said all they could do was escalate my case to the decision makers / processing. Said I should wait a week and someone should call me.
No one did. Two weeks later I call. Lady I speak with tells me her team leader is speaking with a department ? Processing or something they are trying to get someone to call me back with a decision. They say they are sending my letter to the Hackney office and they will call me same day. They called back - but the Hackney office explained as my claim was previously dealt with by the Horsham office - it complicates things and has to go to a different office - not Hackney - for a decision to be made. This is how I understand it. He said he would send my letter to a different office and that I should try and call main number again thursday or friday.
That was yesterday.
Has anyone else had problems like this?
They seem to be passing the buck / or waiting for me to give up!
It takes a lot of energy and time to be on this stuff. I can't believe over 5 months has gone by and I have not received a decision negative or positive. So therefore I cannot move forward.

Is there anything else I can do?
Thanks Beck