Kelly uses contracts as they see fit

It's like this: In April 2015 I signed a NEW contract with Kelly stating that I started working there on 1 April 2015 until 30 April 2019. There are no mentiones of the previous contracts that I had with Sizano (taken over by Kelly).<br> In the contract it clearly states that this is a new job which commenced on 1 April 2015. The previous contract was not valid anymore since Sizano does not exist anymore, and by right my leave day balance should have been paid out back then. Neither I nor Kelly gave any attention to this.<br> At the moment I have given almost 3 weeks notice at my job (since my contract specifies that 1 week notice should be given in the first 6 months) and Kelly does not accept this because they say that I have been working here for longer than that. <br> Kelly plans to take 6 days of my leave to compensate for the 4 week notice period and then pay out the balance, but by right they should pay me the leave balance that was owed to me at the end of March 2015 and allow me to give them one week notice.<br> <br> I pointed out the flaw in their contract, and they said it will be rectified (which means that they know there is a flaw). I would like to see their response on this issue.