Fired After 7 Days - Project Analyst Generis Employee Review

I was fired after 7 days working for the company because it 'wasn't a personality fit'. My manager, the COO, offered me six weeks notice. He said that 'we'll look after you financially', since 'we should have recognised this at interview'. However, a week after termination, the CEO told me I would only be paid one week notice, per the contract, saying 'we fired you due to failing at your job'. I don't think this is an acceptable way to treat graduates.