Not heard of Certificate in 7mo since approval

[firestalker21]

Update: Still didn't receive a reply, but at least there is a faint hope of getting one.

I called UKVI at 0300 790 6268 and they said I should try contacting the Home Office again, and if I get no reply in 20 working days, they will involve someone higher up. I don't know why trying to contact the UKVI in 4 different ways in not enough, but they suggested sending a physical letter with [name, dob, app ref no] to Nationality UKVI PO box 306 Liverpool L2 0QN. (by the way, does this postcode look strange to you?)
I know they won't reply, I just hope in 20 days they will accept to finally escalate the issue (it will have been more than 10 months since acceptance and 15 months since applying)

[nnn15]

Update: Still didn't receive a reply, but at least there is a faint hope of getting one.

I called UKVI at 0300 790 6268 and they said I should try contacting the Home Office again, and if I get no reply in 20 working days, they will involve someone higher up. I don't know why trying to contact the UKVI in 4 different ways in not enough, but they suggested sending a physical letter with [name, dob, app ref no] to Nationality UKVI PO box 306 Liverpool L2 0QN. (by the way, does this postcode look strange to you?)
I know they won't reply, I just hope in 20 days they will accept to finally escalate the issue (it will have been more than 10 months since acceptance and 15 months since applying)

And no response on the complaint? No response from the MP office?

[firestalker21]

No, and no, unfortunately. No answer from anyone. So when the 20 days will have passed, I will need to put them on the spot over the phone to take some action.

[firestalker21]

Hi all thanks for all the moral support in here. I just received yesterday the invitation letter after 10+ months of waiting (the application was approved in June 2020). I've never been so happy to receive such an average-looking piece of paper. I have the ceremony next week.

I am not sure if they reacted to any of my 100 attempts (including contacting the MP, complaining on their website, emailing 4 addresses a bazillion times and also sending a physical letter) or if my turn finally came, but at least it's done. Good luck to everyone!

[firestalker21]

I got my British passport now and everything eventually worked ok.
My MP received an answer from the Home Office saying they are sorry and there was an administration error. No explanation on why they never wrote back. They still didn't reply to any of my letters, and it's a disgrace really that after all my effort they only found fit to write to my MP and nothing to me directly.
In any case, it seems the MP method works. It is a bit slow, but much faster than the Home Office speed. So I would like to thank everyone, in particular to nnn15 who suggested reaching out to my MP (I would never have considered it).