Hollard insurance under regent client services life

I have two hollard policies which I joined through one of their sales consultants that came to my work place selling their products ,when I called the consultant to help me cancel the policy due to it being not the package that I wanted he since said his not working for hollard anymore I have called them giving them my particulars to cancel but they are still deducting ,I have called them to ask them to stop deducting but they have ignored my complaint which is a strain on my budget I have also asked for a cancellation letter from them and also submitted my email they promised to email me the cancellation letter they have not its now 6 weeks that I've been waiting on them still no response from them , I cant reverse their debit order because they are deducting straight from my persal number