A while back I joined Company A. I gave them an email containing a scan of the last page of the contract with my signature before I joined on-site. On there it specifically say's a 3 months notice period.
I've now found a new job and informed Company B that I've got a 3 months notice period. I went through an exit interview with Company A however and I've been now informed that my notice is in fact 1 month by HR (through word of mouth).
Essentially what I think has happened is the first day when I joined the company on-site they asked me to sign the contract for their records. The contract I signed for their records on site actually had a 1 month notice period (instead of 3 the for the one I had given them over email before starting on-site).
Company B want me to join ASAP and they're aware of the 3 months notice period.
I think Company A has now realised their mistake and are not replying to my emails to confirm my official end date.
I obviously would prefer to leave ASAP so the 1 month notice works fine for me.
I understand this isn't a website discussing contractual law matters but I really don't know how to approach this. How should I go about this to try and get the 1 months notice in writing? I'm in the UK.
Edit:
I now have it in writing (email) that my notice period is 1 month. Thanks guys!