Grant of probate timescales

Keg4

Hello All, just wondered if anyone could offer any advice on how to progress my grant of probate application.
Submitted by solicitors Feb, 2020, chased after 8 week period to find they had misplaced on e of the forms and put the application on stop in March and not notified us.  They accepted an electronic copy in April, (as they had misplaced the original).  We are now at the end of May 21 and still (despite the solicitors chasing them up) they cannot provide us with a timeline for completion.
I myself rang the helpline to be told as we were using a solicitor , that they couldn't discuss with me due to data protection.  Unbelievable - I am am executor of the estate and daughter of the deceased.
I have emailed the probate office with a formal complaint and requested that they initiate their formal complaints process.  Yet I cant seem to find out what this is!  I have kept my solicitor informed of this also.  I am also in the process of writing to my local MP to raise the awareness of the 1000's of probate applications that are all well overdue, hoping he can subsequently get some action.
Whilst we wait, this is costing the estate money.  I cannot sell the property, increased solicitors costs etc etc.  I really dont know what else i can do...........any suggestions please?