Tier 2 visa curtailment

Hi everybody can anyone advise
I received a letter from HO regarding variation of my leave to 60 days as my sponsor has informed HO that he has ceased my employment backdated. the day I received the HO office letter I was working , but the problem is my employer was not paying me properly neither he has given me any documents regarding my employment , no payslips etc just was paying cash I think he even did not informed HMRC regarding my employment. Now he informed the Home Office that my employment is ceased backdated after three days of issue of my Tier 2 visa. My questions are:
what are my options for further application , I am trying to go for Tier1(Enterprniour ) visa for which maintenance requirement is for 90 days whereas I got only 60 days, if i keep the money same day i receive the letter I could not complete 90 days, so whats the option.
Secondly can file any complaint against the employer if yes where