Please help

[Saikat]

My husband received Indefinite Leave to Remain in December 2018, then we contacted with Home Office to active my FLR (M) pending application. As a settled person he sponsored (£18,600) for my application with sending new documents (bank statements, payslips, cohabitation letters, English language requirements etc),
Surprisingly, Home Office, refused my application promptly after receive the documents HO refused FLR (FP) that we did not apply.
I do not know why HO is not considering her FLR (M) application that i applied in 2016 according to the immigration rules. I gave biometric, paid health surcharge and application fees and fulfilled all the other requirements.I am living UK continuously since 2011 as a tier 4 dependant and never travelled outside of UK until now, followed Home Office’s rules and regulations and still going to report at Becket house in London regularly since 2016.
I did not breach any immigration rules, no criminal convictions.
Home Office did not mention any explanation, why they are not considering FLR (M) application.
sent again pre-action protocol letter to Home Office’s legal department. But again Home office failed to explain why they are not considering FLR (M) pending application. And ignoring the correspondence, making delay to response.
Home Office’s response:
Home Office withdraw the wrong refusal letter issued on 8 February’2019 and considering FLR (FP) 10 years route. Where as we are competent to get visa on FLR (M) basis, 5 years route.

partner route of Appendix FM.

As stated in our Letter Before Claim (which has resulted in this reconsideration), our client was lawfully in the UK until 13 January 2016 when her spouse application was refused. Our client re-submitted on 20 January 2016 and so benefits from paragraph 39E in that any breach of overstay should be disregarded as her application was made within the relevant grace period (at that time, 28 days). Our client meets all of the requirements of Appendix FM and has provided evidence of her relationship, financial circumstances, English language ability and accommodation.

Our client therefore requests consideration under the 5-year Appendix FM route.