I've posted about this elsewhere. But it probably isn't clear enough. So I will try to summarise.
I am employed, full time, and off work sick. Prior to being off sick I was on maternity leave for 6 months (26 weeks). I went straight from maternity leave to sick leave. My sick pay is 5 months full pay, 5 months half pay. I am currently in month 4 and will be returning to work in the next 3 weeks.
In June I received a letter telling me that I was not entitled to SSP. The reason for this was because I had been on maternity leave prior.
It enclosed and SSP1 form to complete and send to the Jobcentre. I was a little confused as I would receive full pay whether I was entitled to SSP or not. It made no difference to my pay.
Payroll weren't that sure either as it isn't something they are used to dealing with apparently.
I rang the helpline number on the SSP1 form to ask for advice. The woman I spoke to was not helpful and just kept saying we don't know anything until we have all your details. She extrapolated as much information as she could from me, and put the details through some system. She said I was entitled to ESA contribution based. I explained again that I hadn't called to ask was I entitled, I had called because I wanted to know what the letter meant, why I couldn't get SSP, and how it would affect me.
She told me I had to send my sick notes to them. That I would have to attend an ATOS medical, and work focused interviews to get me back to work. The ATOS medical would decide if I was fit to work or not
.
I was quite upset at the phone call (she even tried telling me I should make a claim through the CSA for one of my children
) so I rang payroll back and told them the above. They said to me that none of this sounded right, and to ring back and speak to someone else.
So I did. And the man I spoke to told me that I wasn't entitled to anything as I was on full pay - which was my understanding. And that the woman hadn't listened to me when I had rung earlier. He said I didn't need to do anything unless I went down to half pay. He said he would cancel the claim and that was the end of the matter. I should ignore the claim forms sent in the post, and not send anything back to them. A further letter would be sent telling me the claim was withdrawn.
All sorted?
No. I checked my bank at the weekend to find I had been paid ESA twice. 
I have spent the morning trying to get to the bottom of the matter.
First phone call - sorry, it's our error, we will get back to you and let you know how we have sorted this out. No you are not entitled.
Second phone call - sorry, it's our error, we do not know how it happened. We will cancel the claim now, and you will receive a letter telling you who to pay the money back to.
3 minutes later, the same person I spoke to in the second call rang back to say, actually, yes you are entitled to it. On top of your wage --which isn't right even if I was entitled!
. He couldn't explain why exactly, but that due to my contributions I was entitled.
I rang payroll, who have no idea either. But they have said now they will be deducting the money from my wages.
BUT I STILL DON'T FECKING KNOW IF I SHOULD BE GETTING IT IN THE FIRST PLACE!! More to the point - I don't want it!
I don't want it because I will not be able to send my medical sick note to them - it must go to my employer.
And most of all, I don't want ATOS questioning me over my fecking fanjo (the reason I am off is because of my huuuuuuuuuuuuge, not fully healed, painful episiotomy).
So my employer deducts the money, but then what if I wasn't entitled again then it is me who will lose out! I'd rather not claim anything, and just be paid by my employer as I am being right now.
I've got a sodding headache just thinking about it.
Congratulations if you reached the end.
Seems so pointless given I am back to work very soon. 