Solicitor guided me wrongly.

[MohamedSheriff]

Hi Folks
I am currently residing in UK with Tier2-General visa for 5years till 2021 (A-rated sponsorship)
I applied Tier-2 General PBS dependant for my wife in INDIA on my own.
It got rejected first time due to not providing enough evidence of subsisting marriage. I lost my application fee.

And second time I contacted a solicitor xxxxxxxxxxxxxxxx. They treated me soo worse. Second time when they applied for my wife visa they sent show me the application before submitting. When I asked them to show me to check before submitting they said its all correct and no need to check it again. I believed them and gave my bank details to do the payment. But after doing the payment and coming back home I got the filled application to my mail address. There was a lot of mistakes in it. I went back to them and said I want to withdraw the application and I forced them to withdraw it. They treated me like i they dint do a mistake and I am pressuring them on this application.

Since I have paid £750 as the solicitor fee and they refused to give it back I did the application with them again. They filed the application again. And they guided me to submit all the application to Sheffield home office address. I said thats a wrong method since I produced all the docs in India during my 1st time. They said its the new rule by home office. So they submitted all the documents to sheffield through post.
It got rejected stating I have not demonstrated any documents. When I went and spoke to her stating its her mistake and return my application fee back she refused to do it.

How can I sue that solicitor ?
It has been a month this happened.
And I have planned to submit my application again.
Whom should I talk with to sue that solicitor ?
Which is the best complaints number for this ?
Im depressed that my wife visa got rejected twice and I have lost a lot of money.
Please guide me in the correct path