It would be necessary to know, and you still haven't explained, the background to your "5 year residence permit" 2007-12 . On what basis did you get it, work, family, etc? What happened to your 2004 work permit, was it Business & Commercial and did it expire in 2007?
If you are unsure about your immigration history you could get it from the HO by making a SAR request:
https://www.gov.uk/government/publicati ... mmigration
Another problem is that your employer's sponsor licence may be revoked because they allowed you to work illegally and then they would not be able to sponsor you at all.
Does your current 30 day leave have any endorsement about not being allowed to work?