You are being made redundant but they are going about it unlawfully, which means that you could have a claim for unfair dismissal and probably also unlawful discrimination on the grounds of sex/maternity.
They are going about it all wrong and are not following legal procedure. I suspect they know this but are trying to keep you in the dark so that you don't do anything about it. Not unheard of at all, especially if the employee is absent on leave or maternity leave.
In order to benefit from your rights and to protect yourself and in order to make a claim against them you MUST seek proper legal advice from an employment solicitor ASAP.
The deadline for taking action against an employer is three months less one day and before that you must have exhausted all appeal and grievance procedures, attempted to negotiate and attempted conciliation through ACAS. Deadlines are very very rarely extended.
Most employment solicitors do a free initial consultation to assess the strength of the cars and can often then do a no win no fee type of arrangement.
Most home /contents insurance policies also include legal protection. You need to phone them up, check you're covered, they do an assessment of the case and then they assign you a solicitor if they're going to be able to assist.
Don't whatever you do hand your notice in however tempting it might be. You're just giving them on a plate what they want and you are unlikely to be protected as much as if you stayed in post. You may lose some of your rights too and constructive dismissal is harder to prove than unlawful redundancy and maternity discrimination.
Print out all emails you have received and sent in the matter to and from them and also make a chronological and completely factual list of what happened when, with dates, details, "emailed X asking for Y, no response received" that kind of thing.
I hope you get somewhere with this. It's quite natural to feel overwhelmed with the situation which is every good reason to ensure you have a lawyer working on your behalf for when it gets too much to cope with. A decent solicitor will see you for free initially and then tell you straight your chances and about fees etc and tell you about how to find out about insurance or no win no fee set ups. The most daunting thing can be the prospective cost but if you have a strong case then there's no need to worry as costs can be dealt with in other ways.
I'm going through almost the same thing with my employer at the moment. I'm on long term pregnancy sick leave and my role has been split up between others. Employer is not following redundancy procedure at all and seems to be unaware that pregnancy (like maternity) is a protected characteristic. I am taking them to tribunal for unfair dismissal (not proper redundancy) and sex discrimination. I'm legally trained and have in the past practised employment law, which they seem to have forgotten about!
I really wish you the very best. If you want to pm then go ahead. Please keep us posted and we'll do our best to support you!


