I month ago I handed in my 1 month notice and was placed on garden leave. I was advised that I had to be available to work for the company at any point.
Whilst on garden leave I started work at my new company with a view that I would get paid twice.
My old company called the HR department of the new company and asked what my start date was and found out that I had started whilst on garden leave. They are now refusing to pay me the last months wages and commission which equates to about £4,000 stating that I was not available for work.
This is not the case as my new employer agreed that if my old company needed me to work he would make me available.
So are my old company allowed to do this even though I was available and that was the reason they gave for withholding payments?